Abbott-Smith Manual Greek Lexicon
πῆχυς (G4083)
4 πῆχυς , -εως , gen. pl., -ῶν (for Att. -εων , v. WH, App. , 157; Thackeray, Gr. , 151; Deiss., BS , 153), [in LXX chiefly and freq. for אַמָּה ;] the forearm (Hom.). As a measure of length, a cubit : Mt 6:27 , Lk 12:25 , Jo 21:8 , Re 21:17 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain