If a widow has not remarried within a few months of her husband's death, and the lord's land is in danger of being neglected as a consequence, she will be ordered to choose a capable husband before the next meeting of the manorial court -- normally within three weeks. If she does not, the bailiff or the reeve will select a suitable man for her. If the parties refuse to marry, they will be fined and, if they continued to refuse, imprisoned until they do consent.A widow with sons old enough to do the work, or other relatives willing to pitch in, could get away with not remarrying -- all the lord cared about was that the work be done. But the assumption was that this was the husband's job, and a man would be found to do it.
The quotation is from The Time Traveler's Guide to Medieval England by Ian Mortimer (2008), which I will be writing about soon.