On the wedding night or when buying an animal1 du'a
When any of you marries a woman or purchases a maid-servant then let him say: O Allah, I ask You for...
(اللَّهُمَّ إِنِّي أَسْأَلُكَ خَيْرَهَا وَخَيْرَ مَا جَبَلْتَهَا عَلَيْهِ وَأَعُوذُ بِكَ مِنْ شَرِّهَا وَشَرِّ مَا …
"When any of you marries a woman or purchases a maid-servant then let him say: O Allah, I ask You for the …"