I will redeem you. — The idea of God purchasing, or redeeming, Israel is here brought forward for the first time. Later on we learn that the redemption was accomplished in a twofold way — (1) by the long series of wonders, culminating in the tenth plague, whereby they were taken out of Pharaoh’s hand, and ceased to be his slaves, becoming instead the servants of God; and (2) by being led through the Red Sea, and thus delivered, one and all, from impending death, and so purchased anew. (See Exodus 15:13-16.) The delivery from Pharaoh typified our deliverance from the power of Satan; the bringing forth from Egypt our deliverance from the power of sin.
With a stretched out arm. — See the comment on Exodus 3:20.
Witn great judgments. – That the “wonders” to be performed would also be “judgments” is here first declared plainly, though previously hinted at (Exodus 3:20; Exodus 4:23). In Genesis God had said that he would “judge” the nation which should afflict Israel (Genesis 15:14), but not that he would do so miraculously.