Therefore shall ye lay up these my words. — The same injunctions are found above (Deuteronomy 6:6-9). The Jewish commentator remarks, somewhat sadly, here, that they would remember them in their captivity, if not before. The “therefore” at the commencement of the verse is a simple “and,” so that the passage can be read in connection with what precedes: “Ye will perish quickly from off the good land, and ye will lay these my words to your hearts.” But the words of Deuteronomy 11:21 seem to show that this is not the primary meaning — only an application suggested, like many other applications of Scripture, by the actual event.
Related Commentaries of Deuteronomy 11:18
Deuteronomy 11:18
18 Therefore shall ye lay up these my words in your heart and in your soul, and bind them for a sign upon your hand, that they may be as frontlets between your eyes.