Sahih Bukhari
Merits of the Helpers in Madinah (Ansaar)
Volume: 005 / Book Number: 058 / Hadith Number: 131
Narrated Zaid bin Al-Arqam:
The Annwar said, "O Allah's Apostle! Every prophet has his own followers and we have followed you. So will you invoke Allah to let our followers be considered from us (as Ansar too)?" So he invoked Allah accordingly.