What were the promises made to Jesus in his work of redemption?

Thanks for your question. Since the promises made to God the Son by God the Father were within a covenant, some brief definitions are necessary before we answer the actual question.

What is a covenant?

A covenant is simply an enforceable agreement between two parties. Within it certain things are promised and obligations owed. We observe covenants throughout the Bible. There are numerous covenants that are also observed within the Godhead and therefore recognized within Covenant Theology. These are the Covenant of Works, the Covenant of Grace, and the Covenant of Redemption.

Let's attempt to briefly review these covenants with a brief summary of the references listed below:

What is the covenant of works?

The Covenant of Works was a probationary period for man. While man in Adam was originally created "very good" (Gen. 1:31) - as holy, righteous, and good (cf. Rom. 7:12) mdash; he still was able to sin. Adam was able and was suppose to obey God; his destiny being contingent upon this obedience. So, in the Covenant of Works man wasn't earning anything, rather he was tested according to and in what he already possessed. If Adam had resisted the temptation in the Garden (Gen. 3), he would have passed the test and God would have rewarded him with eternal life. However, the first Adam failed (Hos. 6:7) and original sin came upon the entire human race (Rom. 5:12-21), except Jesus Christ.

What is the Covenant of Grace?

The covenant of grace is a holy covenant made between God the Father (the offended party), and sinful man (the offending party), with Jesus Christ serving as the Mediator between the two (1 Tim. 2:5-6). Because of deadly sinfulness of sin (Rom. 3:23; 6:26), a sinless Mediator (2 Cor. 5:21; Heb. 4:15; 1 Pet. 2:22; 1 John 3:5) is necessary to bring the offended and offending parties together. That Mediator is Jesus Christ alone. In this covenant, God promised to freely and graciously give sinful mankind salvation and eternal life through Jesus Christ (Ezek. 36:26-27; Acts 13:48; Rom. 8:3). The only thing God requires in return is faith in Him - a free gift (John 6:44; Rom. 10:9-10). This gift of faith trusts in the active and passive work of Jesus Christ for their salvation (1 Cor. 15:1-4; 1 Tim. 3:16); not in their own works, efforts, or merit, etc. (Eph. 2:8-9; Tit. 3:4-7). Grace is emphasized because salvation cannot be earned or merited. So, Jesus Christ, the second and last man Adam (1 Cor. 15:45, 47), is the substitute who stood in the place of His people and fulfilled the requirements of the Covenant of Works that Adam was unable to fulfill (Num. 7:64; Isa. 53; Rom. 4:25; 5:12-21; 8:3; 1 Cor. 1:30; 2 Cor. 5:21; Gal. 3:13; Heb. 4:15; 7:26; 1 John 3:5).

What is the Covenant of Redemption?

The Covenant of Redemption is an eternal covenant made between the God the Father and God the Son made before the foundation of the world (cf. Eph. 1:4-5; 1 Pet. 1:20-21). In it the Father agreed to give the Son a particular people to be His own (John 6:37-40). In return, the Son agreed to redeem this specific people (Matt. 25:34; Luke 10:20; Rev. 5:9; 13:8; 17:8) and to serve as their "prophet" (Deut. 18:15; Acts 3:22-23; cf. Matt. 13:57; Luke 13:33), "priest" (Heb. 6:20; 9:11; cf. Eph. 5:2; Heb. 9:26-27; 10:12; 1 John 1:7), and "king" (Matt. 2:2; 21:5; 27:11). So, the covenant was according to the definite plan and foreknowledge of God (Acts 2:22-23; Phil. 2:5-11; e.g. John 4:34; 5:30, 36; 14:31; 17:4). Because they are so closely related, the Covenant of Grace and the Covenant of Redemption are often used as synonyms for one another, however the Covenant of Works and the Covenant of Grace are the means through which the Covenant of Redemption are carried out and fulfilled in redemptive history.

So, what work was assigned to the Son of God? What promises were made to the Son? Charles Hodge and others answered these questions some time long ago. According to Hodge:

As the exhibition of the work of Christ in the redemption of man constitutes a large part of the task of the theologian, all that is proper in this place is a simple reference to the Scriptural statements on the subject.

The work assigned to the Redeemer:

(1) He was to assume our nature, humbling himself to be born of a woman, and to be found in fashion as a man. This was to be a real incarnation, not a mere theophany such as occurred repeatedly under the old dispensation. He was to take on flesh and body, to be bone of our bone and flesh of our flesh, made in all things like unto his brethren, yet without sin, that he might be touched with a sense of our infirmities, and able to sympathize with those who are tempted, being himself also tempted.

(2) He was to be made under the law, voluntarily undertaking to fulfill all righteousness by obeying the law of God perfectly in all the forms in which it had been made obligatory on man.

(3) He was to bear our sins, to be a curse for us, offering himself as a sacrifice, or propitiation to God in expiation of the sins of men. This involved his whole life of humiliation, sorrow, and suffering, and his ignominious death upon the cross under the hiding of his Father's countenance. What he was to do after this pertains to his exaltation and reward.

The Promises made to the Redeemer:

Such, in general terms, was the work which the Son of God undertook to perform. The promises of the Father to the Son conditioned on the accomplishment of that work, were,

(1) That he would prepare him a body, fit up a tabernacle for him, formed as was the body of Adam by the immediate agency of God, uncontaminated and without spot or blemish.

(2) That he would give the Spirit to him without measure, that his whole human nature should be replenished with grace and strength, and so adorned with the beauty of holiness that he should be altogether lovely.

(3) That he would be ever at his right hand to support and comfort him is the darkest hours of his conflict with the powers of darkness, and that he would ultimately bruise Satan under his feet.

(4) That he would deliver him from the power of death, and exalt him to his own right hand in heaven; and that all power in heaven and earth should be committed to him.

(5) That he, as the Theanthropos [God-Man] and head of the church, should have the Holy Spirit to send to whom he willed, to renew their hearts, to satisfy and comfort them, and to qualify them for his service and kingdom.

(6) That all given to him by the Father should come to him, and be kept by him, so that none of them should be lost.

(7) That a multitude whom no man can number should thus be made partakers of his redemption, and that ultimately the kingdom of the Messiah should embrace all the nations of the earth.

(8) That through Christ, in him, and in his ransomed church, there should be made the highest manifestation of the divine perfections to all orders of holy intelligence throughout eternity. The Son of God was thus to see of the travail of his soul and be satisfied.

References:

A'Brakel, Wilhelmus. The Christian's Reasonable Service. "The Covenant of Redemption Between God the Father and God the Son Concerning the Elect; or, the Counsel of Peace."
Bavinck, Herman. Reformed Dogmatics.
Berkhof, Louis. Systemic Theology. "The Covenant of Redemption."
Berkouwer, G.C. Studies in Dogmatics. "Divine Election."
Blake, Thomas. The Covenant of God.
Dabney, Robert. Systematic Theology. "The Covenant of Redemption" and "The Covenant of Grace."
Edwards, Jonathan. Observations Concerning the Scripture Economy of the Trinity and Covenant of Redemption.
Gillespie, Patrick. The Ark of the Covenant Opened.
Hodge, Charles. The Covenant of Grace - Covenant of Redemption.
Muller, Richard. Toward the Pactum Salutis: Locating the Origins of a Concept.
Rutherford, Samuel. The Covenant of Life Opened.
Vincent, Thomas. An Explanation of the Assembly's Shorter Catechism.
Vos, Geerhardus. The Covenant of Redemption: A Covenant Distinct from the Covenant of Grace.
Willard, Samuel. The Doctrine of the Covenant of Redemption.
Witsius, Herman. The Economy of the Covenants between God and Man.

Related Topics:

What is the Covenant of Grace?
The Re-Newed or New Covenant?