Barnes' Notes on the Whole Bible

The oath with which God vouchsafed to confirm His promises to the patriarchs (compare Genesis 22:16; Hebrews 6:13-14) contained by implication these gifts of holiness and eminence to Israel (compare the marginal references).

This is the climax. As the Exodus from Egypt was as it were the birth of the nation into its covenant relationship with God, so the return to the house of bondage is in like manner the death of it. The mode of conveyance, “in ships,” is added to heighten the contrast. They crossed the sea from Egypt with a high hand. the waves being parted before them. They should go back again cooped up in slaveships.

There ye shall be sold - Rather, “there shall ye offer yourselves, or be offered for sale.” This denunciation was literally fulfilled on more than one occasion: most signally when many thousand Jews were sold into slavery and sent into Egypt by Titus; but also under Hadrian, when numbers were sold at Rachel’s grave Genesis 35:19.

No man shall buy you - i. e. no one shall venture even to employ you as slaves, regarding you as accursed of God, and to be shunned in everything.