The pledge

This verse refers to responsibility for someone else's debt or for some other obligation. It can end in abject poverty or even slavery if you cannot pay. For example, Judah volunteered to personally guarantee the safe return of Benjamin to Jacob and when this seemed impossible, he had to offer himself to a slave to Joesph as a salve. Such an arrangement was sealed by "striking hand," equivalent to our handshake.

Proverbs 11:15

 Whoever puts up security for a stranger will surely suffer,
    but whoever refuses to shake hands in pledge is safe.