Arabic text
عن أبي هريرة رضي الله عنه: أَنَّ رَجُلًا قَالَ لِلنَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ: أَوْصِنِي، قَالَ: «لَا تَغْضَبْ» فَرَدَّدَ مِرَارًا قَالَ: «لَا تَغْضَبْ».
Translation
Abu Hurayrah (may Allah be pleased with him) reported: A man came to the Prophet (may Allah's peace and blessings be upon him) and said: "Advise me." He said: "Do not get angry." He repeated that several times, and every time, he would say: "Do not get angry."
Explanation
One of the Companions (may Allah be pleased with them) asked the Prophet (may Allah's peace and blessings be upon him) to direct him to something that would benefit him. He instructed him not to get angry. This means he should avoid the things that would make him angry and should restrain himself in case he becomes angry, not going to excess in his anger by killing, beating, cursing, and so on. The man repeated his request for advice several times, and the Prophet (may Allah's peace and blessings be upon him) said no more in his advice than "Do not get angry".
Source: HadeethEnc.com