The Arabic inscription contains a famous saying of Muhammad as well as the date and reads as follows:
I am the city of Knowledge and 'Ali is the gate - Completed in the blessed month of Ramazan 1112
which translated means:

I am the city of knowledge and 'Ali is the gate thereto. Completed in the blessed month of Ramadan 1112 AH (= February/March 1701 C.E.)