Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with him) that Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) intended to travel and said: "O Messenger of Allah! Advise me." The Prophet (peace and blessings be upon him) said: "Worship Allah and do not associate anything with Him." He said, "O Prophet of Allah! Advise me further." The Prophet (peace and blessings 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 more advice." The Prophet (peace and blessings be upon him) said: "Remain steadfast, and your character should be good."