Saad, may Allah be pleased with him, considered himself superior to those of lower rank, so the Prophet ﷺ said, "Are you given victory and provision except through your weak ones?"
رأى سعد رضي ٱلله عنه أن له فضلا على من دونه فقال النبي ﷺ: هل تنصرون إلا بضعفائكم.
Bukhari narrated it in the Book of Jihad and Expeditions (2896) from Sulayman bin Harb, who said, Muhammad bin Talha related to us, from Talha, from Musab bin Saad, who said, then he mentioned it.Hafiz said in Fath al-Bari (6/88), "The apparent form of this account is mursal, because Musab did not live in the time of this saying, but it is to be understood that he heard it from his father..."Nasai narrated it (3178) through the route of Masaar, from Talha bin Musarrif, from Musab bin Saad, from his father, that he thought he had merit over those beneath him among the companions of the Prophet ﷺ, so the Prophet of Allah ﷺ said, "Allah only grants victory to this nation because of its weak ones, through their supplication, their righteousness, and their sincerity."Its chain of transmission is sahih.