Jeremiah 2:21

A noble vine - Properly, a Sorek vine (see Isaiah 5:2), which produced a red wine Proverbs 23:31, and had a lasting reputation Genesis 49:11.

A right seed - literally, “a seed of truth,” i. e., true, genuine seed, not mixed with weeds, nor with seed of an inferior quality. Compare Matthew 13:24.

How then art thou turned - Or, “How then” hast thou changed thyself “unto me” (i. e., to my hurt or vexation) “into the degenerate” branches “of a strange vine?” The stock, which was God’s planting, was genuine, and of the noblest sort: the wonder was how such a stock could produce shoots of a totally different kind Deuteronomy 32:32.