When the Noble Prophet (s.a.w) conquered Mecca, he announced a general amnesty for all the people – except a few individuals, who were to be killed whenever found; amongst these were ‘Abdullah Ibn Zab’ari, who used to satirize him (s.a.w), Wahshi, who had killed his uncle Hamzah in the battle of Uhud9, ‘Ikramah Ibn Abi Jahl, Safwan Ibn Umayyah and Habbar Ibn al-Aswad – all of whom he eventually pardoned after they were brought before him (s.a.w).
As for Habbar Ibn al-Aswad, he was the person who frightened Zainab – the Noble Prophet’s (s.a.w) daughter, who had been sent towards Madinah by her husband, Abu al-Abbas Ibn Rabi’ – on the way to Madinah as a result of which she suffered a miscarriage. Subsequent to this act of his, the Noble Prophet (s.a.w) had declared it permissible to shed his blood.
After the conquest of Mecca he approached the Noble Prophet (s.a.w), expressed regret over his misdeed and, seeking forgiveness, said: “O’ Prophet of Allah! We were of the polytheists, however Allah, by means of you, guided us aright and delivered us from perdition, so disregard my ignorance and that which you have heard about me, and pardon me!”
The Noble Prophet (s.a.w) said: “I pardon you. Allah has exhibited kindness towards you in that He has guided you into Islam; with the acceptance of Islam, bygones become bygones.”( Shaytan, vol. 1, pg. 412 )