Yahweh will render to every man his righteousness and his faithfulness; because Yahweh delivered you into my hand today, and I wouldn't put forth my hand against Yahweh's anointed.
The main lesson of chapter 26 appears in 1 Samuel 26:23: "the Lord will repay" (cf. Proverbs 20:22; Proverbs 24:29; Romans 12:17; Romans 12:19). The Lord Jesus Christ is our greatest example of one who trusted the Father to vindicate Him (cf. Luke 23:46). Our vindication does not always come in this lifetime, as David’s did. Sometimes it comes after death, as Jesus’ did. Another great revelation is God’s patience with Saul. God gave him many opportunities to repent and to experience God’s blessing within the sphere of his judgment (cf. 1 Samuel 15:26), but Saul did not repent.