The Seal of the Hands did more than list what the Elect could not do, it made a whole religious community depend on a class of members who kept none of the Elect's own restrictions. Because harvesting, grinding grain, pressing fruit and cooking all counted as wounding the Light held in plant matter, an Elect member could not feed himself without breaking his own seal, so the Hearers took on that labor as a religious duty rather than an ordinary chore. A Hearer who grew, prepared and brought food to the Elect was understood to be transferring merit toward his own eventual liberation, since the digestion of the Elect, by which Light was said to be freed from matter, counted as an act performed on the Hearer's behalf as much as the Elect's own.
That division shaped how Manichaean communities were organized wherever they took root, from North Africa in Augustine's own time to Central Asia and China centuries later. The Elect were typically itinerant or communal, unable to farm, own land in the ordinary sense, or marry, and structurally reliant on Hearer households that could. Augustine's later hostility drew directly on having watched the arrangement from inside, as a Hearer for roughly a decade before his conversion, which is one reason his account of the practical mechanics of the two ranks, however unsympathetic its tone, is treated as informed rather than merely invented.