For if ... proved steadfast (ei gar ... egeneto bebaio). Condition of first class, assumed as true. Through angels (di aggelwn). Allusion to the use of angels by God at Sinai as in Acts 7:38Acts 7:53 ; Galatians 3:19 , though not in the O.T., but in Josephus (Ant. XV. 156). Transgression and disobedience (parabasi kai parakoh). Both words use para as in pararuwmen, refused to obey (stepping aside, para-basi as in Romans 2:23 ), neglect to obey (par-akoh as in Romans 5:19 ), more than a mere hendiadys. Recompense of reward (misqapodosian). Late double compound, like misqapodoth ( Hebrews 11:6 ), from misqo (reward) and apodidwmi, to give back. The old Greeks used misqodosia. Just (endikon). Old compound adjective, in N.T. only here and Romans 3:8 .