John Gill Commentary Deuteronomy 30:1

"And it shall come to pass, when all these things are come upon thee, the blessing and the curse, which I have set before thee, and thou shalt call them to mind among all the nations, whither Jehovah thy God hath driven thee," — Deuteronomy 30:1 (ASV)

And it shall come to pass, when all these things are come upon
you
Declared, pronounced, foretold, and prophesied of in the three preceding chapters, especially in (Deuteronomy 28:1–68) ;

the blessing and the curse which I have set before you ;
the blessings promised to those that pay a regard to the will of God and obey his voice, and curses threatened to the see (Deuteronomy 28:1–20) ;

and you shall call [them] to mind among all the nations whither the
Lord your God has driven you ;
recollect the promises and the threatenings, and observe the exact accomplishment of them in their captivities, and especially in this their last and present captivity.