'Negotiator' in the Bible

But, as a matter of fact, the ministry which Christ has obtained is all the nobler a ministry, in that He is at the same time the negotiator of a sublimer covenant, based upon sublimer promises.

For this reason He is the Mediator and Negotiator of a new covenant [that is, an entirely new agreement uniting God and man], so that those who have been called [by God] may receive [the fulfillment of] the promised eternal inheritance, since a death has taken place [as the payment] which redeems them from the sins committed under the obsolete first covenant.

and to Jesus the negotiator of a new Covenant, and to the sprinkled blood which speaks in more gracious tones than that of Abel.