Petrus van Mastrich commenting on Exodus 34:6, from volume 2 of his Theoretical-Practical Theology:

“The goodness of God…designated as (1) love, which is nothing except goodness as it is communicative of itself [i.e. love is God giving his goodness]; (2) grace, which is nothing but love that is not owed; (3) mercy, which is nothing but grace toward the miserable; (4) longsuffering, which is nothing but patience that is long-lasting; and (5) kindness, which is nothing but longsuffering with beneficence. And these are the affections of the gracious God, about which Moses speaks in Exodus 34:6.”