Hippolytus of Rome, Exegetical Fragments §5: On Numbers

Now, in order that He might be shown to have together in Himself at once the nature of God and that of man,—as the apostle, too, says: “Mediator between God and men, the man Christ Jesus. Now a mediator is not of one man, but two,”—it was therefore necessary that Christ, in becoming the Mediator between God and men, should receive from both an earnest of some kind, that He might appear as the Mediator between two distinct persons.