C. F. Keil and Franz Delitzsch on Jeremiah 37:13

Jer 37:13

When he was entering the gate of Benjamin, where Jeriah the son of Shelemiah kept watch, the latter seized him, saying, "Thou desirest to go over to the Chaldeans" (נפל אל־, see on Jer 21:9). The gate of Benjamin (Jer 38:7; Jer 14:10) was the north gate of the city, through which ran the road to Benjamin and Ephraim; hence it was also called the gate of Ephraim, 2Ki 14:13; Neh 8:16. בּעל, "holder of the oversight," he who kept the watch, or commander of the watch at the gate. "The accusation was founded on the well-known views and opinions of Jeremiah (Jer 21:9); but it was mere sophistry, for the simple reason that the Chaldeans were no longer lying before the city" (Hitzig).