Netsach (H5322) is a richly multivalent Hebrew word meaning: (1) perpetuity/forever/endurance, (2) eminence/excellence/victory, and (3) in Isaiah 63:3, the juice/blood of grapes (pressed out in God's wrath). The musical notation lamnatsach (to the chief musician) uses this root.
Netsach appears in some of the most powerful declarations of confident faith in Hebrew Scripture. 'The Netsach of Israel will not lie or have regret' (1 Sam 15:29) — God's eternal constancy as the anchor of promise. In Lamentations 3:18, Jeremiah laments 'my endurance (netsachi) has perished from the LORD' — only to recover by verse 21. The word also crowns the Psalms as a musical instruction: lamnatseach (to the choirmaster/for victory) over 55 psalms. This is no accident — Israel's worship was oriented toward the eternal, victorious God whose purposes endure forever.