Solomon
Ecclesiastes 5:19ESV·traditional attribution

Everyone also to whom God has given wealth and possessions and power to enjoy them, and to accept his lot and rejoice in his toil—this is the gift of God.

Matthew Henry Presbyterian @wholebiblehenry

Solomon, from the vanity of riches hoarded up, here infers that the best course we can take is to use well what we have, to serve God with it, to do good with it, and take the comfort of it to ourselves and our families; this he had pressed before, Ecc 2:24; Ecc 3:22. Observe, 1.

Commenting on Ecclesiastes 5:18-20

John Gill Reformed Baptist @doctorgill

Every man also to whom God hath given riches and wealth,.... Which include the whole of a man's substance; all his estate, personal and real; and all his goods and possessions, movable and immovable, as gold, silver, cattle, fields, and farms; which are all the gift of God, by whatsoever means they may be acquired or possessed; and hath given him power; or, "caused him...

Jamieson-Fausset-Brown Reformed @jfbcommentary

As Ecc 5:18 refers to the "laboring" man (Ecc 5:12), so Ecc 5:19 to the "rich" man, who gets wealth not by "oppression" (Ecc 5:8), but by "God's gift." He is distinguished also from the "rich" man (Ecc 6:2) in having received by God's gift not only "wealth," but also "power to eat thereof," which that one has not.