βεβαιόω
bebaioō
beb-ah-yo'-o
From G949; to stabilitate (figuratively)
KJV Usage: confirm, (e-) stablish.
G1226 διαβεβαιόομαιδιαβεβαιόομαι
diabebaioomai
dee-ab-eb-ahee-o'-om-ahee
Middle voice of a compound of G1223 and G950; to confirmthoroughly (by words), that is, asseverate