When any of you marries a woman or purchases a maid-servant then let him say:
Allāhumma innī as'aluka khayrahā
wa khayra mā jabaltahā `alayh,
wa a`ūdhu bika min sharrihā
wa sharri mā jabaltahā `alayh.
When any of you marries a woman or purchases a maid-servant then let him say :
O Allah, I ask You for the goodness of her,
and the goodness upon which You have created her,
and I seek refuge in You from the evil of her,
and from the evil upon which You have created her.
If you purchase a camel then take hold of the top of its hump and say the same.
Reference:
Abu Dawud 2/248 and Ibn Majah 1/617. See also Al-Albani, Sahih Ibn Majah
1/324.
