Who was Abu Sufyan? Why did Muhammad, sallallaahu 'alayhi wa sallam, say that whomsoever sought refuge in the house of Abu Sufyan would have mercy upon him?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.

Abu Sufyaan is Sakhr ibn Harb Al-Qurashi. He was a noble Companion, and Ibn Al-Atheer said about him in Usd Al-Ghaabah fi Ma’rifat As-Sahaabah:

“Abu Sufyaan is Sakhr ibn Harb ibn Umayyah ibn ‘Abd Shams ibn ‘Abd Manaaf Al-Qurashi Al-Umawi. He was born ten years before the Year (incident) of the Elephant and was one of the noble people of Quraysh. He was a trader and used to equip the merchants with his money and the money of Quraysh to Syria and other non-Arab countries.

Abu Sufyaan embraced Islam on the eve of the Conquest (of Makkah), and he took part in the battle of Hunayn as well as in the battle of Taaif with the Prophet where he lost sight in one of his eyes (because of an injury to it). On the day of the battle of Yarmook, he lost sight in his second eye.

He took part in the Battle of Yarmook under the banner of his son Yazeed.

Abu Sufyaan was among those whose hearts were softened towards Islam, and he became a good Muslim.

He died during the Caliphate of ‘Uthmaan, in the year 32 A.H; and it was said that he died in the year 33 A.H. It was also said that he died in the year 31 A.H; and another view states that he died in the year 34 A.H.

Caliph ‘Uthmaan performed the funeral prayer on him. It was also said that his son Mu’aawiyah performed the funeral prayer on him. He died at the age of eighty-eight years old, and it was said that he was ninety-three years old. There are other opinions about his age when he passed away.” [abridged]

As regards the saying of the Prophet on the day of the conquest of Makkah, “Whoever enters the house of Abu Sufyaan is safe;” then this was because Abu Sufyaan was a new Muslim, and the Prophet wanted to soften his heart towards Islam and show his honorable and noble status because he was one of the leaders of Quraysh. An-Nawawi, in his commentary on the saying of the Prophet in Saheeh Muslim “Whoever enters the house of Abu Sufyaan is safe.”, said, “This was to soften the heart of Abu Sufyaan and to show his noble status.”

Allaah knows best.