John Trapp on Psalms 25:10

Verſ. 10. All the paths of the Lord are mercy and truth] All the paſſages and proceedings, both ordinantiall and providentiall whereby he cometh and communicateth himſelf to his people, are not only Mercy (though that's very ſweet) but Truth; they come to them in a way of a promiſe from God, as bound to them by covenant, this is ſoul-ſatisfying indeed; this turns all that a man hath to cream, when every mercy is a preſent ſent him from Heaven by vertue of a promiſe.

Ʋnto ſuch as keep his Covenant, and his Teſtimonies] i.e. His Law (that ſingular Teſtimony of his goodneſſe towards them) called a Covenant, becauſe hee bargaineth with us, as it were, that wee ſhould keep it; which becauſe wee can never do, he undertaketh to perform his own part, and ours too. Lex jubet, gratia juvat, he worketh all our works in us, and for us; he giveth us to be what he biddeth us to be; this is the everlaſting Covenant, and the fruits of it are ſure mercies, compaſſions that fail not.