Nehemiah 2:15

The brook. Probably the Kidron Valley. By riding up the valley Nehemiah could see high above him the ruined walls of Jerusalem. This was probably on a night of full moonlight. Otherwise, he would not have been able to see much, because there is considerable distance between the eastern wall on the escarpment of the southern hill and the bed of the Kidron Valley, in which he rode.

Turned back. It is not known how far Nehemiah followed the Kidron Valley northward. His survey of the wall probably did not include that part of it to the east of the Temple. He may have already known the extent of damage existing there, from previous visits to the Temple area. Retracing his steps all the way back to the Valley Gate, Nehemiah and his few companions (v. 12) re-entered the city unnoticed.