Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) intended to travel and said: O Messenger of Allah! Advise me with some counsel. The Prophet (peace and blessings of Allah be upon him) said: "Worship Allah and do not associate anything with Him." He said, O Prophet of Allah! Give me more advice. The Prophet (peace and blessings of Allah be upon him) said: "Whenever you do an evil deed, immediately follow it with a good deed." He said, O Prophet of Allah! Give me further advice. The Prophet (peace and blessings of Allah be upon him) said: "Remain steadfast and make your character good."