'Pledge' in the Bible

Zacchaeus however stood up, and addressing the Lord said, "Here and now, Master, I give half my property to the poor, and if I have unjustly exacted money from any man, I pledge myself to repay to him four times the amount."

And more than that, we ourselves, though we possess the Spirit as a foretaste and pledge of the glorious future, yet we ourselves inwardly sigh, as we wait and long for open recognition as sons through the deliverance of our bodies.

In the same way, when the meal was over, He also took the cup. "This cup," He said, "is the new Covenant of which my blood is the pledge. Do this, every time that you drink it, in memory of me."

and He has also set His seal upon us, and has put His Spirit into our hearts as a pledge and foretaste of future blessing.

And He who formed us with this very end in view is God, who has given us His Spirit as a pledge and foretaste of that bliss.

that Spirit being a pledge and foretaste of our inheritance, in anticipation of its full redemption--the inheritance which He has purchased to be specially His for the extolling of His glory.