Matthew Poole and continuators on Genesis 38:18

18 And he said, What pledge shall I give thee? And she said, Thy signet, and thy bracelets , and thy staff that is in thine hand: and he gave it her, and came in unto her, and she conceived by him .

Or, handkerchief, or girdle, or any other ornament made of twisted thread which the Hebrew word signifies.

God so ordering things by his Providence, that his sin might be discovered. And this and other such horrid crimes committed sometimes by the Patriarchs and other eminent persons it hath pleased God for divers wise and holy reasons to leave upon record, partly to discover how great and deep the corruption of mans nature is, and that even in the best; partly to oblige all men to an humble sence of their own infirmity, and to a diligent application of themselves to God for his gracious succors, and to a greater circumspection and watchfulness to prevent those evils in themselves; partly to encourage even the greatest sinners to repentance and the hope of Pardon; and partly for the just punishment and obduration of incorrigible sinners who make such sad examples matter of their delight and imitation.