In the Latin monastic rules (IV-XI centuries), manual labor is always understood as that undertaken by the monk to counteract idleness and sloth, that is, with a noneconomic purpose. Manual labor contributes to spiritual growth, but it is different from work for the sustenance of the community. The purpose of this contribution is to clarify this difference, beginning with the famous motto ora et labora (par. 1). In fact, only after this clarification is it possible to understand how the early Christian monk is above all a spiritual “inoperative,” who is explicitly precluded from those tasks that serve the livelihood of the monastery (par. 2). The only labor worthy of the name is the opus Dei (par. 3.), while others, mostly lay people, are entrusted with the task of put the community’s assets to good use (par. 4.).