Jamieson, Fausset & Brown

God, who is rich--Greek "(as) being rich in mercy." for--that is, "because of His great love." This was the special ground of God's saving us; as "rich in mercy" (compare Eph 2:7; Eph 1:7; Rom 2:4; Rom 10:12) was the general ground. "Mercy takes away misery; love confers salvation" [BENGEL].