Matthew Poole and continuators on Exodus 34:6

6 And the LORD passed by before him, and proclaimed, The LORD, The LORD God , merciful, and gracious, long-suffering, and abundant in goodness and truth .

This title shews his glorious being, power and authority, the following titles note his goodness to men.

In fulfilling all his gracious promises made to Abraham and to his seed and to all his people, wherein he is said to be abundant, because he generally is better than his word and gives more than he promised. There is a truth in divine threatnings, but here the scituation of this word in the midst of the Attributes of divine Goodness plainly shews that it is to be restrained to the promises, this being usual and reasonable, that general words have their signification limited by the context. And indeed here seems to be a Hendyadis, goodness and truth, for true, sincere and hearty goodness, as mercy and truth, are oft put for true and real mercy. See Psal. 25. 10. and 57. 3. &c.