The messenger of Allah (ﷺ) said: If you buy a camel, then you should take hold of it’s hump and say:

اَللَّهُمَّ إِنِّي أَسْأَلُكَ خَيْرَهَا وَخَيْرَ مَا جَبَلْتَهَا عَلَيْهِ وَأَعُوْذُ بِكَ مِنْ شَرِّهَا وَمِنْ شَرِّ مَا جَبَلْتَهَا عَلَيْهِ

Allaahumma 'innee 'as'aluka khayrahaa wa khayra maa jabaltahaa 'alayhi wa 'A'oodhu bika min sharrihaa wamin sharri maa jabaltahaa 'alayhi

O Allah, I ask You for the goodness of it and the goodness upon which You have created it, and I seek refuge in You from the evil of it and from the evil upon which You have created it.

Reference: Hasan. Abu Dawud: 2160