isaiah 65:16 That he who blesseth himself in the earth shall bless himself in the God of truth; and he that sweareth in the earth shall swear by the God of truth; because the former troubles are forgotten, and because they are hid from mine eyes. - Free Bible Online

      16. That he--rather, "he who," &c.
      blesseth, &c.-- (Ps 72:17; Jer 4:2).
      God of truth--very God, as opposed to false gods; Hebrew, Amen: the very name of Messiah (2Co 1:20; Re 3:14), faithful to His promises (Joh 1:17; 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; De 6:13; Ps 63:11).
      troubles--that is, sins, provocations [LOWTH]. Rather, calamities caused by your sins; so far from these visiting you again, the very remembrance of them is "hid from Mine eyes" by the magnitude of the blessings I will confer on you (Isa 65:17, &c.). [MAURER].

JFB.