Sahih al-Bukhari 6380
Sahih al-Bukhari · Book 80: Invocations · To invoke for increase of offspring, along with His Blessings.
Narrated Anas:
حَدَّثَنَا أَبُو زَيْدٍ، سَعِيدُ بْنُ الرَّبِيعِ حَدَّثَنَا شُعْبَةُ ، عَنْ قَتَادَةَ ، قَالَ سَمِعْتُ أَنَسًا ـ رضى الله عنه ـ قَالَ قَالَتْ أُمُّ سُلَيْمٍ أَنَسٌ خَادِمُكَ. قَالَ " اللَّهُمَّ أَكْثِرْ مَالَهُ وَوَلَدَهُ، وَبَارِكْ لَهُ فِيمَا أَعْطَيْتَهُ " .
Um Sulaim said (to the Prophet), "Anas is your servant; so please invoke for Allah's blessings for him." He said "O Allah! Increase his wealth and offspring, and Bless (for him) whatever You give him."