Why would this specific cry be called 'a Psalm to bring to remembrance'? It suggests this isn't a one-off prayer, but something vital to recall.
Commentators point out that this Psalm is almost identical to a section in Psalm 40. This repetition isn't accidental. It signifies that David (or whoever prayed this) faced similar crises multiple times.
This Psalm, then, serves as a powerful reminder: God's faithfulness in the past is a basis for trusting His help in the present. It's a prayer form that can be revisited, bringing to mind previous deliverances and reinforcing the belief that God will act again. It's a tool for the people of God to remember their reliance on Him, especially when facing new troubles.