Into the inner prison (ei thn eswteran pulakhn). The comparative form from the adverb esw (within), Ionic and old Attic for eisw. In the LXX, but in the N.T. only here an ( Hebrews 6:19 . The Roman public prisons had a vestibule and outer prison and behind this the inner prison, a veritable dungeon with no light or air save what came through the door when open. One has only to picture modern cells in our jails, the dungeons in feudal castles, London prisons before the time of Howard, to appreciate the horrors of an inner prison cell in a Roman provincial town of the first century A.D. Made their feet fast (tou poda hspalisato autwn). First aorist (effective) middle of aspalizw, from aspalh (safe), common verb in late Greek, in the N.T. only here an ( Matthew 27:64-66 . The inner prison was safe enough without this refinement of cruelty. In the stocks (ei to xulon). Xulon, from xuw, to scrape or plane, is used for a piece of wood whether a cross or gibbet ( Acts 5:30 ; Acts 10:39 ; Acts 13:29 ; Galatians 3:13 ; 1 Peter 2:24 ) or a log or timber with five holes (four for the wrists and ankles and one for the neck) or two for the feet as here, xulopedh, Latin vervus, to shackle the feet stretched apart ( Job 33:11 ). This torment was practiced in Sparta, Athens, Rome, and Adonirom Judson suffered it in Burmah. Xulon is also used in the N.T. for stick or staff ( Matthew 26:47 ) and even a tree ( Luke 23:31 ). Tertullian said of Christians in the stocks: Nihil crus sentit in vervo, quum animus in caelo est (Nothing the limb feels in the stocks when the mind is in heaven).