'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 when they had received a pledge from Jason and the others, they released them.

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."

who also sealed us and gave us the Spirit in our hearts as a pledge.

Now He who prepared us for this very purpose is God, who gave to us the Spirit as a pledge.

who is given as a pledge of our inheritance, with a view to the redemption of God’s own possession, to the praise of His glory.

Physical exercise is of limited value, but Godliness is very dear, a pledge of life, both there and here.

and will therefore receive condemnation because they have renounced their original pledge.

And so, having patiently waited, he realized the promise [in the miraculous birth of Isaac, as a pledge of what was to come from God].

Baptism, which corresponds to this, now saves you (not the removal of the filth of the flesh, but the pledge of a good conscience toward God) through the resurrection of Jesus Christ.