Amr bin Salama reported,

He then narrated the hadith in full, in which it was said, "The Arabs were holding back from accepting Islam, waiting for the Conquest. They would say, 'Leave him and his people alone. If he prevails over them, then he is a truthful prophet.' So when the Conquest took place, every people hastened to embrace Islam, and my father Ubayy was the first among my people to embrace Islam."

Azami 13786

Sahih

عن عمرو بن سلمة قال

فذكر الحديث بطوله، وجاء فيه: وكانت العرب تلوم بإسلامهم الفتح، فيقولون: اتركوه وقومه، فإنه إن ظهر عليهم فهو نبي صادق، فلما كانت وقعة أهل الفتح بادر كل قوم بإسلامهم، وبدر أبي قومي بإسلامهم.

الأعظمي 13786صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Tafsir of the great Quran
Chapter
Tafsir of Surah Kafirun
Section
His saying, "When the help of Allah and the victory come, and you see the people entering the religion of Allah in multitudes"
Numbering
Jami al-Kamil 13786 (2nd edition)
Azami 13786