At Lystra (en Lustrois). Neuter plural as in Act 16:2; 2Ti 3:11 while feminine singular in Act 14:6, Act 14:21; Act 16:1. There was apparently no synagogue in Lystra and so not many Jews. Paul and Barnabas had to do open-air preaching and probably had difficulty in being understood by the natives though both Greek and Latin inscriptions were discovered here by Professor Sterrett in 1885. The incident narrated here (Act 13:8-18) shows how they got a real hearing among these rude heathen.
There sat (ekathēto). Imperfect middle of kathēmai. Was sitting. This case is very much like that in Act 3:1-11, healed by Peter. Possibly outside the gate (Act 13:13) or some public place.
Impotent in his feet (adunatos tois posin). Old verbal, but only here in the N.T. in this sense except figuratively in Rom 15:1. Elsewhere it means “impossible” (Mat 19:26). Locative case. Common in medical writers in the sense of “impotent.” So Tobit 2:10; 5:9.
Had walked (periepatēsen). So best MSS., first aorist active indicative “walked,” not periepepatēkei, “had walked” (past perfect active).