al-Qadi `Iyad said in his book al-Shifa', section "Revering the Prophet after his death":
Mus`ab ibn `Abd Allah said:
Imam Malik, whenever the Prophet (s) was mentioned, his color would change, and he would incline his body until those who were sitting with him felt discomfort. This was mentioned to him and he said: "If you had seen what I have seen you would not blame me for what you see now. I used to see Muhammad ibn al-Munkadir--and he was the master of the scholars (sayyid al-qurra')--and we dared not ever ask him about a hadith except he wept until we pitied him."
Without any discussion of the authenticity, accepting this narration on the authority of Qadi `Iyad, we can infer several important points, without taking this as fiqh in any way:
First is that people may find such a display of emotion as that evoked by Imam Malik strange and even consider in their minds that it is disapproved of in shari`ah, as adduced from the narrator's words: "until those who were sitting with him felt discomfort."
Second is that when a person is in a state of `ishq or extreme love to Allah subhanahu wa ta`ala and His Prophet (s), he cannot be blamed for his actions which appear in him as a result of that intense love. And this is adduced from Malik's words "If you had seen what I have seen you would not blame for what you see now."
Third is that showing intense emotion, to the point that it affects one's physical appearance and actions, is not forbidden in Islam, rather, when spontaneous and sincere, evoked by the remembrance of one beloved, is a sign of true faith and great yaqeen (certainty). And this can be adduced by Malik's words "I used to see Muhammad ibn al-Munkadir--and he was the master of the scholars (sayyid al-qurra')--and we dared not ever ask him about a hadith except he wept until we pitied him." His affirmation that Muhammad ibn al-Munkadir was master of the scholars, is Imam Malik's way of saying that "if he accepted to fall into such a state of intense weeping, and he was my teacher and the master of all the scholars of Madina, then who can blame me if a similar state obtains in me?" This is enough to show that such a display can not by any means be considered a manifestation of shirk, nor is it bida`, but when it appears spontaneously, from love or fear or other intense emotion, is acceptable and blameless.
Fourth is that such a display of emotion, when evoked sincerely and not for show, is not limited by any specific form of action or physical effect, but is whatever appears in a person in terms of movements, weeping, exclamations, shaking and so on. And this is adduced from the narrator's words "his color would change, and he would incline his body " and from Imam Malik's words "he wept until we pitied him."
Fifth is that the use of the term sayyid for the Prophet (s) and for other than the Prophet (s) is permissible and is an action done by, and therefore promoted by one of the earliest great masters of fiqh, Imam Malik (ra), as in his words, "and he was the master of the scholars (sayyid al-qurra')."
Further narrations of the reverence of other great Tabi`een and pious predecessors are found in the book of Ibn Qunfudh al-Qusantini al-Maliki (d. 810) Wasilat al-islam bi al-nabi `alayhi al-salat wa al-salam:
"It was the practice of the Pious Predecessors and the Imams of the past that whenever the Prophet was mentioned in their presence they were overwhelmed by reverence, humbleness, stillness, and dignity. Ja`far ibn Muhammad ibn `Ali ibn al-Husayn ibn `Ali ibn Abi Talib (Ja`far al-Sadiq) would turn pale whenever he heard the Prophet mentioned. Imam Malik would not mention a hadith except in a state of ritual purity. `Abd al-Rahman ibn al-Qasim ibn Muhammad ibn Abu Bakr al-Siddiq would turn red and stammer whenever he heard the Prophet mentioned. As for `Amir ibn `Abd Allah ibn al-Zubayr ibn al-`Awamm al-Asadi (note: one of the many early Sufis), he would weep until his eyes had no tears left in them. When any hadiths were mentioned in their presence they would lower their voices. Malik said: 'His sacredness (hurmat) is in death is as his sacredness was in life.'"
Source: Abu al-`Abbas Ahmad ibn al-Khatib, known as Ibn Qunfudh al-Qusantini al-Maliki, Wasilat al-islam bi al-nabi `alayhi al-salat wa al-salam (The means of Islam with the Prophet, peace be upon him) (Beirut: Dar al-gharb al-islami, 1404/1984) p. 145-146.
And Allah knows best,