Behold, I send a messenger before thee. Jewish commentators regard the messenger as Moses, who, no doubt, was a specially commissioned ambassador for God, and who might, therefore, well be termed God's messenger.
But the expressions—"He will not pardon your transgressions," and "My name is in him," are too high for Moses. An angel must be intended—probably "the Angel of the Covenant,"—whom the best expositors identify with the Second Person of the Trinity, the Ever-Blessed Son of God.
To keep thee in the way is not simply "to guide thee through the wilderness, and prevent thee from geographical error," but to keep thee altogether in the right path. s, to guard thy going out and thy coming m, to prevent thee from falling into any kind of wrong conduct.
The place which I have prepared is not merely Palestine, but that place of which Palestine is the type—viz; Heaven. Compare John 14:2:—"I go to prepare a place for you."