اَللَّهُمَّ أَكْثِرْ مَالَهُ وَوَلَدَهُ وَبَارِكْ لَهُ فِيمَا أَعْطَيْتَهُ

Allaahummakthir maa-lahu wa waladahu wa baarik lahu fiimaa a-'ataitahu

O Allah! Increase his wealth and children, and bestow Your Blessing on whatever You give him. Anas ibn Malik (RA) said, "My mother took me to the Messenger of Allah (ﷺ), and said, 'O Messenger of Allah!' Pray to Allah for this little servant of yours, Anas. Then the Prophet (ﷺ) said: (The dua is mentioned above)

Reference: Bukhari: 6344