1 Samuel 26:20

Now therefore, let not my blood fall to the earth before the face of the Lord: for the king of Israel is come out to seek a flea, as when one doth hunt a partridge in the mountains.

Cross-reference

1 Samuel 2:9 promises God guards the feet of his faithful — directly relevant to David's plea not to fall far from God's presence.

1 Samuel 24:14 uses the exact same 'flea' metaphor David repeats here, highlighting his consistent self-deprecation before Saul.

1 Samuel 25:29 directly reassures David that God will bind his life securely despite pursuers — the same situation he now faces.

In 1 Samuel 24:11, David makes the same point to Saul — that he is hunted unjustly — after the cave incident.

In 2 Samuel 9:8, Mephibosheth calls himself a 'dead dog' — like David calling himself a 'flea', both use humble animal imagery.