To invoke for increase of offspring, along with His Blessings.

Sahih al-Bukhari · Book 80 · Hadith 6380, 6381

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 ‏"‏‏.‏

Narrated Anas: 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."