when you marry a woman or buy a maidservant, you should say:
اللّهُـمَّ إِنَّـي أَسْـأَلُـكَ خَيْـرَها، وَخَيْـرَ ما جَبَلْـتَهـا عَلَـيْه، وَأَعـوذُ بِكَ مِنْ شَـرِّها، وَشَـرِّ ما جَبَلْـتَهـا عَلَـيْه.
Allahumma innee as-aluka khayraha wakhayra ma jabaltaha AAalayh, wa-aAAoothu bika min sharriha washarri ma jabaltaha AAalayh.
‘O Allah, I ask You for the goodness within her and the goodness that you have made her inclined towards, and I take refuge with You from the evil within her and the evil that you have made her inclined towards.’
…and if you buy a camel, then you should take hold of it’s hump and say likewise.’