Tertullian

"But when the fulness of time was come, God sent forth His Son" -the God, of course, who is the Lord of that very succession of times which constitutes an age; who also ordained, as "signs" of time, suns and moons and constellations and stars; who furthermore both predetermined and predicted that the revelation of His Son should be postponed to the end of the times.

Since, then, the Creator promised the gift of His Spirit in the latter days; and since Christ has in these last days appeared as the dispenser of spiritual gifts (as the apostle says, "When the fulness of the time was come, God sent forth His Son; " and again, "This I say, brethren, that the time is short" ), it evidently follows in connection with this prediction of the last days, that this gift of the Spirit belongs to Him who is the Christ of the predicters.