Sahih Bukhari Volume 4, Book 56, Hadith 2897

حَدَّثَنَا سُلَيْمَانُ بْنُ حَرْبٍ، حَدَّثَنَا مُحَمَّدُ بْنُ طَلْحَةَ، عَنْ طَلْحَةَ، عَنْ مُصْعَبِ بْنِ سَعْدٍ، قَالَ رَأَى سَعْدٌ ـ رضى الله عنه ـ أَنَّ لَهُ فَضْلاً عَلَى مَنْ دُونَهُ، فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ هَلْ تُنْصَرُونَ وَتُرْزَقُونَ إِلاَّ بِضُعَفَائِكُمْ ‏"‏‏

Narrated By Mus'ab bin Sad : Once Sad (bin Abi Waqqas) thought that he was superior to those who were below him in rank. On that the Prophet said, "You gain no victory or livelihood except through (the blessings and invocations of) the poor amongst you."