For you forgot the God of your salvation, and the Rock of your strength you did not remember; because I planted you with pleasant saplings, and with the branch of a stranger you sow it.

כִּי שָׁכַחַתְּ אֱלֹהֵי יִשְׁעֵךְ וְצוּר מָעֻזֵּךְ לֹא זָכָרְתְּ עַל כֵּן תִּטְּעִי נִטְעֵי נַעֲמָנִים וּזְמֹרַת זָר תִּזְרָעֶנּוּ

because I planted you: Because, when I planted you in the beginning, I planted a pleasant planting, twelve sons of Jacob, and when your saplings raised branches, they gave forth improper seed, like strange branches which are not of the species of the vine but resemble the vine.

you sow it: You give your seed into that sapling. [It is also possible to say that “and with the branch of a stranger you sow it,” means that you intermarry with the nations and they mingled with you.]