Abbott-Smith Manual Greek Lexicon
ἐξ-αστράπτω (G1823)
1 † ἐξ-αστράπτω [in LXX: Nu 3:3 ( בָּרָק ), Ez 1:4 ( לָקַח hithp.) 1:7 Da LXX 106 ( קָלַל )* ;] to flash like lightning, gleam, be radiant : ἱματισμός , Lk 9:29 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain