בָּנֶ֨יךָ וּבְנֹתֶ֜יךָ נְתֻנִ֨ים לְעַ֤ם אַחֵר֙ וְעֵינֶ֣יךָ רֹא֔וֹת וְכָל֥וֹת אֲלֵיהֶ֖ם כָּל־הַיּ֑וֹם וְאֵ֥ין לְאֵ֖ל יָדֶֽךָ׃
Tus hijos y tus hijas serán entregados á otro pueblo, y tus ojos lo verán, y desfallecerán por ellos todo el día: y no habrá fuerza en tu mano.
Rashi
וכלות אליהם [AND THINE EYES SHALL SEE] AND LONG FOR THEM — i.e. they will look expectantly for them (the children) that they should return home, but they will not return. — Any desire that does not come to fulfillment is termed a “failing of the eyes” (cf. Deuteronomy 28:65).
Chizkuni
בניך ובנותיך נתנים לעם אחר, “your sons and your daughters will be given to another nation.” According to the Talmud, tractate Yevamot folio 63, here the Torah speaks of the second wife of a father who maltreats his children from his first wife.
Ibn Ezra
you will pine from “longs, indeed it pines” [Psalms 84: 3]. and “David longed” [II Samuel 13: 39].