Having voluntarily undertaken the terms of the everlasting covenant, a special economical relationship was now established between the Father and the Son

Most blessedly were several features of the everlasting covenant typed out in Eden. Let us consider these features:

3. Having voluntarily undertaken the terms of the everlasting covenant, a special economical relationship was now established between the Father and the Son-the Father considered as the appointer of the everlasting covenant, the Son as the God-man mediator, the head and surety of His people. Now it was that the Father became Christ’s “Lord” (Ps. 16:2, as is evident from vv. 9, 11; Mic. 5:4), and now it was that the Son became the Father’s “servant” (Isa. 42:1; cf. Phil. 2:7), undertaking the work appointed. Observe that the clause “took upon him the form of a servant” precedes “and was made in the likeness of men.” This explains His own utterance “as the Father gave me commandment, even so I do” (John 14:31; cf. 10:18;12:49). This accounts for His declaration, “My Father is greater than I” (John, 14:28), wherein our Savior was speaking with reference to the covenant engagement which existed between the Father and Himself.

Arthur W. Pink- The Divine Covenants-Part One-The Everlasting Covenant