Isaiah
Isaiah 65:16ESV·traditional attribution

so that he who blesses himself in the land shall bless himself by the God of truth, and he who takes an oath in the land shall swear by the God of truth; because the former troubles are forgotten and are hidden from my eyes.

Matthew Henry Presbyterian @wholebiblehenry

Here the different states of the godly and wicked, of the Jews that believed and of those that still persisted in unbelief, are set the one over - against the other, as life and death, good and evil, the blessing and the curse. I.

Commenting on Isaiah 65:11-16

John Gill Reformed Baptist @doctorgill

That he who blesseth himself in the earth,.... That is sensible he stands in need of blessings, and wishes for them, and prays he might have them; or that takes notice that he is blessed with them, and acknowledges them, and is thankful for them: shall bless himself in the God of truth; shall pray to him for blessings he wants, and ascribe what he...

Jamieson-Fausset-Brown Reformed @jfbcommentary

That he--rather, "he who," &c. blesseth, &c.-- (Psa 72:17; Jer 4:2). God of truth--very God, as opposed to false gods; Hebrew, Amen: the very name of Messiah (Co2 1:20; Rev 3:14), faithful to His promises (Joh 1:17; Joh 6:32). Real, substantial, spiritual, eternal, as opposed to the shadowy types of the law. sweareth, &c.--God alone shall be appealed to as God (Isa 19:18; Deu 6:13; Psa 63:11).