Rich in mercy. — Not only merciful, but rich “in the multitude of mercy,” as attaching even to those dead in sin (see Chrysostom on this passage). The idea of richness in grace, glory, mercy, is especially frequent in this Epistle. (See Ephesians 1:7; Ephesians 1:18; Ephesians 2:7; Ephesians 3:8; Ephesians 3:16.)
For his great love. — Again, as in Ephesians 1:4, stress is laid on the love of God, before all else, as the one moving cause of salvation. (Comp. Romans 5:8, “God commendeth His love towards us, in that, while we were yet sinners, Christ died for us.”)