Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) said that a man came to the Messenger of Allah (peace and blessings be upon him) and said: "O Messenger of Allah! Tell me a deed by which I may enter Paradise, and let it be brief so that I can grasp it." He (peace and blessings be upon him) said: "Do not get angry."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / 20280