Al-Qaadee ’Iyaadh (d.595H) - rahimahullaah - relates:
"Mus‘ab Ibn ‘Abdullaah said: When Imaam Maalik (d.179H) would mention the Prophet (sallallaahu ‘alayhi wa sallam), his colour would change and he would have to lean down, and those in his gathering would feel disturbed. So one day he was being asked about this and he said: If you had seen what I have seen, you would not have rejected what you had seen. I have seen Muhammad Ibnul-Munkadir (d.130H) - and he was the leader of the reciters - that he would never be asked about a hadeeth, except that he would weep, until we had mercy upon him. And I have seen Ja‘far Ibn Muhammad (d.148H) who used to smile a lot. Yet whenever the Prophet (sallallaahu ‘alayhi wa sallam) was mentioned to him, he would turn pale. I have never seen him relating the Hadeeth of the Messenger of Allaah (sallallaahu ‘alayhi wa sallam), except in a state of purification. And when times deteriorated, I never saw him except in one of three conditions: either praying, observing silence, or reciting the Qur’aan. He never uttered a word having no significance, and he was one of the scholars and worshippers who had great fear of Allaah. Whenever ‘Abdur-Rahmaan Ibnul-Qaasim (d.126H) mentioned the Prophet (sallallaahu ‘alayhi wa sallam), he turned pale as if the blood had been drained from his face, and his tongue dried up due to reverence of the Messenger of Allaah (sallallaahu ‘alayhi wa sallam). I went to ‘Aamir Ibn ‘Abdullaah Ibnuz-Zubayr (d.123H), and when ever the Prophet (sallallaahu ‘alayhi wa sallam) was mentioned to him, he would weep so much, until he was unable to weep any longer. I saw az-Zuhree (d. 124H) - and he was from the kindest people, and closest to them - that when the Prophet (sallallaahu ‘alayhi wa sallam) was mentioned to him, he would not be able to recognize you, nor would you be able to recognize him. I came to Safwaan Ibn Sulaym (d.132H) - and he was one of the Mujtahid scholars and worshippers - that whenever he mentioned the Prophet (sallallaahu ‘alayhi wa sallam), he would weep and he would not stop weeping, to the extent that the people would have to get up and leave him."
Related by Ibn Taymiyyah in Kitaabul-Waseelah (p. 92).