It was narrated from `Aqil bin Abu Talib:
that he married a woman from Banu Jusham, and they said: "May you live in harmony and have many sons." He said: "Do not say that, rather say what the Messenger of Allah said: 'Allahumma barik lahum wa barik `alaihim (O Allah, bless them and bestow blessings upon them).' "
English reference: Vol. 3, Book 9, Hadith 1906
Arabic reference: Book 9, Hadith 1981