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.
Abu Dawud 2/248 and Ibn Majah 1/617. See also Al-Albani, Sahih Ibn Majah 1/324.
Hisnul Muslim 191