A.T. Robertson Commentary Acts 3:17

"And now, brethren, I know that in ignorance ye did it, as did also your rulers." — Acts 3:17 (ASV)

And now (κα νυν). Luke is fond of these particles of transition (7:34; 10:5; 20:25; 22:16) and also κα τα νυν (4:29; 5:38; 22:32; 27:22), and even κα νυν ιδου (13:11; 20:22).

I wot (οιδα). Old English for "I know."

In ignorance (κατα αγνοιαν). This use of κατα occurs in the Koine. See also Phm 1:14. One may see Lu 23:34 for the words of the Saviour on the Cross. "They had sinned, but their sin was not of so deep a dye that it could not have been still more heinous" (Hackett). If they had known what they were doing, they would not knowingly have crucified the Messiah (1 Corinthians 2:8).