Success in achieved with the help of Allah, for He is the Guide by the grace to the straight path! May Allah enable us to achieve what He loves and finds pleasing!

You should know that deputyship(khilafa) is a term for the delegation of a deputy (khalifa) to succeed the Shaykh who was the deputy before him, because he will trasmit to the pupils what the previous Shaykh used to transmit to them, including the remembrances (adhkar), the litanies (awrad), the incantations(ahzab) the secrets (asrar), the techniques of contemplation(tawajjuhat), the goals(maqasid) the spiritual retreats(khalawat), the rules of proper conduct(adab), the sciencies (ulum), and the intuitive cognition (ma'arif). In short, he will do for them, and with them, what the previous Shaykh used to do, and he will be endowed with all the rights over them with which the Shaykh was endowed, by virtue of deputyship and delegation

Suppose that you ask: "What is the difference between the deputy(khalifa) and the appointee(muqaddam)?" The answer is the following:
The appointee (muqaddam) is someone who is commissioned by the Shaykh--or by someone authorized to authorize him, and so on and so on, until Allah inherits the earth and those upon it---to teach the obligatory remembrances as well as some of the remembrances peculiar to the elite, and whose appointment is for a limited term.
Every genuine appointee has a lofty degree, by which he is entitled to obedience and respect.
As for the deputy(khalifa), he is not like that. He is a representative of the Shaykh without restriction. The appointees and their pupils are therefore included among the subjects of the deputy. Obedience to the deputy is incumbent upom them, because the duty of compliance with the deputy and the prohibition of opposition to him are incumbent on all the people of the Spiritual Path. Someone who is taught by the deputy in on an equal footing with someone who is taught by any other, because of the degree of khalifship.
You must know this and act upon it, so that you may be rightly guided. Allah guides whomever He wills to a straight path! If you understand this you should know that I spent a very long time in the company of Sidi Muhammad al Ghali (khalifa of Shaykh Tijani in the Hijaz after the passing of Shaykh Tijani). By His pure grace, Allah instilled love of me in his heart, so I acquired all the contents of his heart and his inner core, and I captured his heart and his outer form. He chose me as a companion and cast other people aside from him. He preferred my as a servant and a doorman, and I became for him an intimate friend and a pupil. I cast aside all the branches of science that I had been memorizing and recording, and stripped myself of the cognitions and facts that I had been collecting and acquiring because of my knowledge that all that is useful to the narrator and others. In spite of this, whenever I requested anything from him with regard to the secrets of the Spiritual Path, he would scold me to be repentant of the request, until Allah prepared me and assisted me to obtain what I was eager to acquire.
While we were in the Prophet's Mosque, he said to me at the time of the forenoon prayer: "You must not make the people appointees in the granting of the litany, As for you, you are a deputy among the deputies of Shaykh Tijani, not one of the appointees. " After that, he informed me that Shaykh Tijani said "I have given Shaykh Umar ibn Sa'id everything he need from this Spiritual Path, meaning the secrets and remembrances, so there is nothing for you to do except to transmit it." He would often look at me after that, while we were sitting together, and he would say: " I swear by Allah that you love Shaykh Tijani" He would also say: "I swear by Allah, the One other than whom there is no god that I shall stand for a long time in the presence of Allah's Messenger and nothing will come from my mouth except supplication on your behalf!"
I saw Sidi Muhammad Ghali by chance after we had parted and I said to him: "O Sidi, you said that I am a deputy among the deputies of the Shaykh, not one of the appointees?" He said to me "Yes, you are a deputy".
Since this had been confirmed you should know that I have evidence to prove that his ancestor, our master Allah's Messenger(Allah bless him and give him peace) loves me, and that I am one of his inheritors and one of his deputies. I also have evidence to prove that Shaykh Tijani loves me with a perfect love, and that I am among those who attain to him and among his deputies( may Allah the Exalted be well pleased with him).
As for the evidence related to Allah's Messenger, it includes the following:
Allah has graciously bestowed on me--by His pure and noble generosity--knowledge of the sciences of the Sacred Law and Reality that I cannot possibly conceal. Allah has said:

O you who truly believe, obey Allah and His Messenger,
and those of you who are in authority, and if you have any dispute
about any matter, refer it to Allah and the Messenger
if you are believers in Allah and the Last Day.
That is better and more seemly in the end(4:59)

According to Ibn Abbas and Jabir, those in authority are the jurists and the scholars who teach the people the knowledge of their religion. This is also the opinion of al Hasan, ad Dahhak and Mujahid. Allah has also said
He is the One who has made you earthly deputies
and has exalted some of you in rank above others,
so that He may try you by what He has given you.
Your Lord is Swift in prosecution,
and He is All Forgiving, All Compassionate (6:165)

---and according ot the commentary entitled al-Arais, He is saying in effect: "I have made you the deputies of the world, after the passage of the time and the ages, and the conclusion of the rotating sphere and the passing centuries, so whatever was allotted to your predecessors in the form of Messengership, Prophethood, dominion and honor, and whatever was at the disposal of those in authority, it will belong to you, O deputies of the Prophets and Champions of the Truth" He is the One who has made you deputies on the earth, like Adam, Noah, Abraham, Moses, and Jesus, and who has increased you honor over the masses with the honor of your Prophet. As for His saying:
And Moses said to his brother Aaron:
"Be my deputy among my people..." (7:142)

Muhammad ibn Hamid said: "The Prophets and the saints have always had deputies to succeed them, among their companions and the members of their community who came after them. Their deputies provide guidance in accordance with their guidance, preserving their exemplary customs when the members of their community neglect them. Abu Bakr was the holder of this station after the Prophet, and I praise be to Allah am one of those who hold it".
Further evidence is provided by the following points:
-Praise be to Allah! I have not consorted with the rulers, and I do not love those who consort with them. As recorded in Tabyin al Maharim , on the authority of Anas, the Prophet said:

The best of the commanders are those who promote the scholars,
and the worst of the scholars are those who promote he commanders. The scholars are the trustees of the Messengers in charge of Allah's servants, so long as they do not consort with the rulers, for if they do that they betray the Messengers. You must beware of them and stay away from them!
-Praise be to Allah! I observe the enjoining of what is right and proper, and the prohibition of what is wrong and improper. As reported in as-Siraj al-Munir, the Prophet once said:
If someone enjoins what is right and proper, and forbids what is wrong and improper, he is Allah's deputy on His earth, the deputy of His Messenger(Allah bless him and give him peace), and the deputy of His Book...
-I once happened to see the Prophet(Allah bless him and give him peace), and he said to me: "Allah has made you one of the best of its people," meaning the best of my Community". I drew near to him, because my heart was filled with joy and delight at that saying, and I said to him: I have accepted and been well pleased, O Messenger of Allah!"
-One of the brethren said the he saw the Prophet(Allah him and give him peace) and he said: "Persist in what you are committed to, and obey your Shaykh Umar, for what you are committed to is true and correct.
-One of the brethren sent me a letter in which he had written: " You should know, O our Shaykh, that I saw you in my sleep, wearing a white shirt, and I heard a speaker say ' This is Allah's Messenger. He has drawn near!' I headed toward the place where I had seen you, and found that the pair of you had met together. You were both shrouded by a mist, so I could not see you clearly. I heard the Prophet addressing you calmly, and I memorized these words" 'I love you with a genuine love, in spite of those around you.' The mist then cleared, and I saw you on an elevated place. You were trying to get down from it, but you were stuck there, as if you had a tremor. Someone else said to you 'Are you awestruck by good tidings?" You said: 'Yes', and you availed yourself of my help in order to climb down."
-One of the brethren mentioned to me that he had seen in his sleep, a person on a throne in a house with two doors, and that person had said to him "O so and so, do you recognize me?" "No", said he, and that person said: "I am Muhammad, the best of humankind!" Then he went on to say (Allah bless him and give him peace)"Iam sending you to your Shaykh Umar. Tell him that I am greeting him with the salutation of peace, so he must summon Allah's servants to the religion of Allah. Let him make clear whatever he seeks to achieve, for I am his guarantor, and let him pay no attention to dodgers, for they are perfidious." He repeated this three time.......
more to be posted Inshallah

- One of the saints was in Medina the Illuminated. He used to ask the Prophet (Allah bless him and give him peace) about everything he was seeking, and the Prophet would inform him about what he asked, so I requested him to ask the Prophet about my spiritual state and about what my business would lead to. He told me after a while that the Prophet had informed him that an adversary of mine, who was extremely hostile toward me, had recently died in my town, so it was incumbent on me to pardon him, because of the severity of the torment he had incurred. I therefore pardoned the adversary. The saint then informed me that the Prophet had said: "Tell Umar that he will suffer a relapse, and when the release is over, he will come together with me."

- The favorite young man and the righteous saint, my brother and my twin, Ali ibn Sa'id saw the Prophet accompanied by our Shaykh Tijani and Sidi Muhammad al Ghali. Sidi Ahmad Tijani was conversing with our master Allah's Messenger. My brother Ali said: "When I wished to ask Allah's Messenger about something, but Sidi Muhammad al Ghali prevented me, I said to Sidi Ahmad Tijani: "How is my spiritual state, O Sidi?" He said: "You will not die until you are a saint." Sidi Miuhammad al Ghali thereupon said to Allah's Messenger: " How is the spiritual state of my brother Umar, O Messenger of Allah?" To this he responded by saying"Umar has begun on my hand, and in it he will end"

-The equitable Imam and the eminent saint, Muhammad Bello ibn al Arif billah Uthman dan Fodio informed me that he wished to ask Allah for good fortune, and to look after my best interests. It happened to him once that he heard a person say. "The Prophet says to you: "You should know that the affairs of Umar ibn Sa'id are in my hand. I manage them for him and I have not neglected them."

-I once saw the Prophet while I was counseling the people and summoning them to Allah with inducement and intimidation. He was present in silence and listening until I said: "The Fire will then come from the direction of the West, so the people will flock to the Place of Assembly. The Prophet then said: " I only statyed silent from the beginning of your speech until now because of your being correct. Then I wished to ask you about that, but reverence prevented me , so I refrained."

-I once saw the Prophet (Allah bless him and give him peace) while I was in a fit of bad temper, so I drew to him and he mentioned several things to me, including the following: "They, meaning the people of the earth on which you were at the time of the vision, do not love happiness!"

-One of the faithful brethren saw him (Allah bless him and give him peace), so it occurred to that brother that the should ask some things of the Prophet, but he said to him before he asked: "Seek from Shaykh Umar ibn Sa'id whatever you are seeking from me!"

-I installed one of the faithful brethren in the secluded retreat, and after spending several days there, he sent me a letter in which he had written: "I saw the Prophet in the retreat, and he was saying to me: "Al Hajj Umar is my trustee, so long as he does not consort with the rulers and meddle with this world, for if he consorts with them and meddles with it, he has betrayed me, so beware of him!"