He doesn’t know the front or back of his own hand
tzehrkeen yehdehvuh ou ahrchevuh chee keedehr
The above indicates a person who is lacking knowledge. It is a way of saying such a person is stupid.
Let him ride on an ass (or horse) and he’ll use it to go to the toilet
Ehssuh teer paghneek gertah
When a person uses their acquired wealth or education for a useless purpose this proverb is used to point out their stupidity. You don’t need to ride on a horse to go to the toilet. Only a fool would ride a horse to the toilet.