Usama ibn Zayd related that one day the Prophet (ﷺ) was riding on a donkey on a straw saddle covered by a blanket from Fadak. Usama ibn Zayd was riding behind him. He was on his way to visit Sa'd ibn 'Ubada. He passed by a meeting which included 'Abdullah ibn Ubayy ibn Salul - before the enemy of Allah had become Muslim. The gathering contained a mixture of Muslims, associaters and idolaters. He greeted them.