Sayyiduna Makhramah bin Nawfal (may Allah be pleased with him) narrates: When the Messenger of Allah (peace and blessings be upon him) made Islam public, the people of Makkah all became Muslim - and this was before the prayer was made obligatory - to the extent that when he (peace and blessings be upon him) recited a verse of prostration they would all prostrate, and because of the crowding one of them could not find room to prostrate. Then the chiefs of Quraysh - al-Walid bin al-Mughirah, Abu Jahl bin Hisham and others - who had been at Ta'if on their land, came back and said: Are you abandoning the religion of your forefathers? And so those people disbelieved.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17138