Mishkat al-Masabih #894

Mu'adh b. Jabal said that God’s Messenger took him by the hand and said, “I love you, Mu'adh,” to which he replied, “And I love you, Messenger of God.” He then told him not to omit to say at the end of every prayer, “My Lord, help me to remember Thee, thank Thee, and worship Thee acceptably.” Ahmad, Abu Dawud and Nasa’i transmitted it, but Abu Dawud did not mention that Mu‘adh said, “And I love you.”