Radak on Genesis
ויקרא ..ויברך אתו, the text of the blessing commences with the words: וא-ל שדי יברך אותך (verse 3).
Haamek Davar on Genesis
Yitzchok called. Yaakov was embarrassed to come to Yitzchok on his own after having deceived him. By calling him Yitzchok conferred his retroactive approval of Yaakov’s deed.
Rav Hirsch on Torah
ויברך אותו, nun freiwillig und mit vollem Bewusstsein. Rebekkas Heilmittel hatte ihm völlig die Augen geöffnet.