Psalms 86:5

"For Thou, Lord, art good and gracious" (ver. 5). ...Even prayers are often hindered by vain thoughts, so that the heart scarcely remains fixed on God: and it would hold itself so as to be fixed, and somehow flees from itself, and finds no frames in which it can enclose itself, no bars by which it may keep in its flights and wandering movements, and stand still to be made glad by its God. Scarcely does one such prayer occur amongst many. Each one might say that this happened to him, but that it happened not to others, if we did not find in the holy Scripture David praying in a certain place, and saying, "Since I have found my heart, O Lord, so that I might pray unto Thee." He said that he had found his heart, as if it were wont to flee from him, and he to follow it like a fugitive, and not be able to catch it, and to cry to God, "For my heart hath deserted me." Therefore, my brethren, thinking over what he saith here, I think I see what he meaneth by "gracious." I seem to feel that for this reason he calls God gracious, because He bears with those failings of ours, and yet expects prayer from us, in order to make us perfect: and when we have given it to Him, He receives it gratefully, and listens to it, and remembers not those many prayers which we pour out unthinkingly, and accepts the one which we can scarcely find. For what man is there, my brethren, who, on being addressed by his friend, when he wishes to answer his address, sees his friend turn away from him and speak to another, who is there who would bear this? Or if you appeal to a judge, and set him up to hear you, and all at once, while you are speaking to him, pass from him, and begin to converse with your friend, who would endure this? Yet God endures the hearts of so many persons who pray and think of different things. ...What then? […]

I said, I will confess, and thou forgavest, Ps. xxxii. (2.) He is a prayer-hearing God; he is plenteous in mercy, very full, and very free, both rich and liberal unto all those that call upon him; he has wherewithal to supply all their needs and is openhanded in granting that supply.

For thou, Lord, art good,....

For thou, Lord, art good, and ready to forgive. Good at giving and forgiving; supplying us with his good, and removing our evil. Here was the great reason why the Psalmist looked to the Lord alone for his joy, because every joy creating attribute is to be found in perfection in Jehovah alone. Some men who would be considered good are so self exultingly indignant at the injuries done them by others, that they cannot forgive; but we may rest assured that the better a being is, the more willing he is to forgive, and the best and highest of all is ever ready to blot out the transgressions of his creatures. And plenteous in mercy unto all them that call upon thee. God does not dispense his mercy from a slender store which perchance may be so impoverished as to give out altogether, but out of a cornucopiae he pours forth the infinite riches of his mercy: his goodness flows forth in abounding streams towards those who pray and in adoring worship make mention of his name. David seems to have stood in the cleft of the rock with Moses, and to have heard the name of the Lord proclaimed even as the great lawgiver did, for in two places in this psalm he almost quotes verbatim the passage in Ex 34:6—"The Lord God, merciful and gracious, longsuffering, and abundant in goodness and truth."

For thou, Lord, art good - I found my expectations of help on thy own goodness through which thou art always ready to forgive. And I found it also on thy well-known character, to which all thy followers bear testimony, viz., that “thou art plenteous in mercy unto all them that call upon thee.”