Psalms 103:8

The Lord is merciful and gracious
So he made himself known to Moses, ( Exodus 34:6 ) , and so David found him to be, and therefore calls upon his soul to bless his name. God is "merciful" in the most tender and affectionate manner; he has bowels of mercy, which yearn towards his people, as those of a tender parent to its child, as the word signifies; his mercy is free, without any motive or merit in men to engage it; he delights in showing it; he constantly bestows it; it is the source of all good things; it is communicated through Christ; all mercies temporal and spiritual come by him; and this lays a foundation for faith and hope: and he is gracious, as appears in the eternal choice of his people to salvation; in providing a Saviour and a ransom for them; in giving all grace and the blessings of it to them in his Son; in giving him for them, and all things to them with him; in justifying them by his righteousness; in pardoning their sins for his sake; in taking them into his family; in regenerating, calling, preserving, and saving them:

slow to anger,
or "longsuffering" ^F4; even to wicked men, to the vessels of wrath, to the old world, yea, to Jezebel, to whom he gave space to repent; which longsuffering being abused and despised, is an aggravation of condemnation: but rather here it intends God's longsuffering to his people, as before conversion, waiting till the time comes that he is gracious to them; and after conversion, notwithstanding their backslidings and revoltings; and this longsuffering is their salvation:

and plenteous in mercy;
large and abundant in it, as appears by the various instances of it, and ways and methods in which he shows it; in election, in the covenant, in redemption, in regeneration, in pardon and eternal life; and by the abundance of it which he bestows on every one of his people; and by the vast numbers which do partake of it.