Imam Musa Al-Kazim (as)
One day 7th Imam, Imam Musa Al-Kadhim (as) was passing by the tent of a Nomad who was a black man. Imam Musa Al-Kadhim (as) went up to him and said "Salam Alaikum", in a warm and friendly manner.
Upon leaving Imam Musa Al-Kadhim (as) said good-bye to him in a very kind manner with these words: "If there is anything I can do for you, I'm more than willing to do it".
One of the followers of 7th Imam, Imam Musa Al-Kadhim (as) who saw this attitude said "Is it suitable for you, the son of the messenger of Allah (SWT), to sit and talk with a man of no reputation and make such an offer as: If you need me in any work, I'm more than willing to do it? Is it right for a man of great dignity to talk to a man like that?"
7th Imam, Imam Musa Al-Kadhim (as) replied, "This is one of Allah's creatures. Allah (SWT) has created all men equal. Besides, as a Muslim, he is our brother in faith. After all, life does not remain the same forever. One who needs help today may be the one who will be able to help us tomorrow when we'll need help! If we don't pay any attention to him today, one day when we may need him we will be embarrassed to ask him for help".
Moral: In Islam everyone...