The Mekhilta, the tannaitic midrash on Exodus, examines a soaring promise from the prophet Isaiah: "Then you will rejoice in the Lord, and I will 'ride' you on the heights of the earth" (Isaiah 58:14). The imagery is extraordinary — God will elevate Israel to ride upon the very peaks of the world. But the rabbis detect something familiar in the language. Isaiah ends the verse with "for the mouth of the Lord has spoken." Where did He speak it?
The Mekhilta identifies the source in the Song of Moses (Deuteronomy 32:13): "He will 'ride' him on the heights of the earth." The identical phrase — riding on the heights — appears in Moses' final poem to Israel, a text that predates Isaiah by centuries. Moses described what God had already done for the people: settled them in the high places, fed them honey from the rock, gave them oil from flint.
The connection reveals a beautiful symmetry. Moses spoke of the heights of the earth as past reality — what God accomplished for Israel in the wilderness and in the early settlement. Isaiah speaks of the same heights as future promise — what God will do again if the people return to righteousness.
The image is the same. The promise is the same. The Mekhilta shows that Isaiah's prophecy of future elevation is simply Moses' description of past glory, projected forward into the messianic age.