Psalm 40:14 asks that those seeking the psalmist's life be put to shame and turned back. The verse belongs to a prayer for deliverance from hostile people intent upon his destruction.
John 18:4-6 records Jesus confronting the armed party that comes to arrest Him in Gethsemane. When He identifies Himself, they draw back and fall to the ground. John does not quote Psalm 40:14, so this should not be described as a direct fulfillment of the psalm's wording. The scene nevertheless provides a striking thematic correspondence: those who come seeking Jesus' life literally draw backward before Him, demonstrating that His arrest occurs not because He is powerless but because He willingly submits to the course appointed for Him.