Whether seven year cycles of life are natural or not, are scientific fact or mythical fantasy is a subject for debate and one that many have engaged in and continue to do so. Certainly many traditions recognise this number as significant, and each of us might be able to identify seven-year cycles of development in our own lives (or seven-year "itches" in our relationships!) Ignoring for now the mysterious properties of the number seven, what we have here is a rhythm of restoration imposed on a seven year cycle. And why not? It's a decent period of time. We know today, and quite likely it was also known in ancient times, that land yields better if not worked too hard. Organic farmers tend to practice crop rotation, and give time for the land to lie fallow. Land in that sense is like the human, or indeed any working animal. The Hebrew people recognised that humans and animals need a rest every seven days, and the land, being longer living and more robust needs a rest every seven years.

Curiously, although we may derive the idea of sustainability, neither Leviticus, nor Exodus mention this ecological advantage explicitly, instead the Exodus passage suggests the sabbath is for a different purpose altogether: to (at least partially) redress social inequity:

And six years thou shalt sow thy land, and shalt gather in the fruits thereof: 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... — Exodus 23:10-11

Whether it is for ecological or social justice (or both) such periods of rest for the land on which we live seems to have been an effective strategy in restoring both the land and the people who worked it. In todays monoculture farming, land is worked to the bone, artificially enhanced by chemicals to squeeze all the life out of it. Today we see land not as our partner but as our slave, treating it accordingly. I wonder what else in my life I treat with such irreverence. We have a throwaway culture today, where objects have built-in obsolescence. We work our radios, kettles, computers, mobile phones, cookers, fridges, and all our other gadgets to death, discarding them when no longer useful. The once-upon-a-time culture of lovingly repairing such objects seems to be long gone. But if land, which is essentially dirt on the ground, needs to be treated with love to serve us well, perhaps other inanimate objects also need such care. Although it seems silly to treat one's mobile phone or toaster with love, it may be that the restoration in such an act is not with the object of affection, but with the subject. In nurturing we ourselves are nurtured, in restoring we are restored.