General Behavior (Kitab Al-Adab)
Dawud :: Book 41 : Hadith 5145
Narrated Abdullah ibn Umar:
A man came to the Prophet (peace_be_upon_him) and asked: Apostle 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.