Charles Ellicott Commentary Judges 9:35

"And Gaal the son of Ebed went out, and stood in the entrance of the gate of the city: and Abimelech rose up, and the people that were with him, from the ambushment." — Judges 9:35 (ASV)

Stood in the entering of the gate of the city. —This was the ordinary station of kings, judges, etc. but Gaal only seems to have gone there in order to keep a look-out (Joshua 20:4).