God, in His covenant with Moses, had instructed Israel to give rest to the land every seven years.¹ Since the institution of kingship in Israel this practice had (apparently²) been neglected, and the land was farmed continuously, selfishly, greedily. It is to this that Jeremiah refers when predicting the length of years that the Israelites would be imprisoned in Babylon. Almost 500 years had passed since King David's ascension, meaning seventy land sabbaths had been neglected. This was the debt Israel had to now pay. By leaving the land altogether the land could redeem its seventy sabbaths, one after the other. Only when the debt was paid could the people of Israel return.

We didn't learn much from this though, did we? For the past 500 years or so we've also been farming the land continuously, selfishly, greedily, and worse, stripping away all the crops of the unfarmed land leaving it bare and desolate. Our debt today is at least as great as Israel's. So prepare for seventy years of enslavement—of denial of liberty. Maybe these Covid months are just the beginning of that period.

¹ But the seventh year thou shalt let it rest and lie still; that the poor of thy people may eat: and what they leave the beasts of the field shall eat. In like manner thou shalt deal with thy vineyard, and with thy oliveyard., Exodus 23:11
² This is not conclusive, but here are a few references to the idea: The Fall of Jerusalem, 70 sabbaths without rest and Daniel's 70 weeks.