Charles Spurgeon Commentary Deuteronomy 32:18

"Of the Rock that begat thee thou art unmindful, And hast forgotten God that gave thee birth." — Deuteronomy 32:18 (ASV)

Of the Rock that begat you, you are unmindful, and have forgotten God that formed you.

Israel was nothing apart from God – a little tribe of people – nothing to be compared with the great nations of the earth. Its only reason for existence was its God. He was its center, its light, its glory, its power. They had got away from him that formed them.