Sahih al-Bukhari, Volume 7, Book 64, Hadith 282 (USC-MSA) ⓘ
Narrated Um Salama: I said, "O Allah's Messenger! Shall I get a reward (in the Hereafter) if I spend on the children of Abu Salama and do not leave them like this and like this (i.e., poor) but treat them like my children?" The Prophet said, "Yes, you will be rewarded for that which you will spend on them."
حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا وُهَيْبٌ، أَخْبَرَنَا هِشَامٌ، عَنْ أَبِيهِ، عَنْ زَيْنَبَ ابْنَةِ أَبِي سَلَمَةَ، عَنْ أُمِّ سَلَمَةَ، قُلْتُ يَا رَسُولَ اللَّهِ هَلْ لِي مِنْ أَجْرٍ فِي بَنِي أَبِي سَلَمَةَ أَنْ أُنْفِقَ عَلَيْهِمْ، وَلَسْتُ بِتَارِكَتِهِمْ هَكَذَا وَهَكَذَا، إِنَّمَا هُمْ بَنِيَّ. قَالَ " نَعَمْ لَكِ أَجْرُ مَا أَنْفَقْتِ عَلَيْهِمْ " .
also referenced under: Book 69, Hadith 19 (In-Book) & Hadith 5369 (DarusSalam)