Majma al-Zawaid 17534 — The believer errs and then returns

Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) reports that the Prophet (peace and blessings be upon him) said: "The parable of faith is like a horse tied with a long rope at its tethering-post: it roams about and then comes back to its place. The believer becomes heedless and then returns to faith. So feed your food to the pious, and the believers are the ones deserving of your kindness."
Ahmad and Abu Ya'la recorded it, and the narrators of both are the narrators of the Sahih, except for Abu Sulayman al-Laythi and Abdullah bin al-Walid al-Tujibi, and both of them are thiqah (trustworthy).