Gevurot 16:23-25

Orthodox Jewish Bible

²³ And having inflicted klop after klop upon these Jewish men, they threw Rav Sha’ul and Sila into the beis hasohar, giving orders to the soher to guard them securely.

²⁴ And the soher, having received such an order, threw them into the inner beis hasohar, and he fastened their feet in the stock. [IYOV 13:27; 33:11; YIRMEYAH 20:2,3; 29:26]

²⁵ And about chatzot halailah Rav Sha’ul and Sila were davening and were singing niggunim to Hashem, and the prisoners were listening to them.