Philemon 1:18

If he hath wronged thee, or oweth thee ought, put that on mine account;

Cross-reference

In Genesis 43:9, Judah becomes a pledge for Benjamin's safe return — a parallel to Paul's offer to guarantee Onesimus's debt.

Psalm 119:122 asks God to be a surety — a parallel to Paul acting as surety for Onesimus's debts.

Proverbs 6:1 warns against putting up security for others — Paul's offer contrasts by willingly becoming surety.