Hadith #5164 (Sunan Abi Dawud)
Book: General Behavior (Kitab Al-Adab)
Narrator(s): Fadayl bin 'Iyyad bin Mas'ud فضيل بن عياض بن مسعود, Hilal bin Yasaf هلال بن يساف, Husayn bin 'Abdur Rahman al-Salmi حصين بن عبد الرحمن السلمي, Masdad bin Masrhad مسدد بن مسرهد بن مسربل
Grade: Sahih

A man came to the Prophet (ﷺ) and asked: Messenger of Allah! how often shall I forgive a servant? He gave no reply, so the man repeated what he had said, but he still kept silence. When he asked a third time, he replied: Forgive him seventy times daily.

Source: https://parallelquran.com/hadith/sunan-abi-dawud-5164/