Gen 22:16

22:16 By myself I have sworn. God reinforces the surety of His infallible promise by an oath (15:8–21; 22:17; cf. Heb. 6:13–18). While sinful and fallible human beings swear by an authority higher than themselves, God, the supreme Being and Authority, swears by Himself (Heb. 6:13 note).

not withheld . . . your only son. Abraham’s action points forward to God’s provision of “his only Son” as the final sacrifice for sin (John 3:16; Rom. 8:32).