An example of this is where you appoint a man to carry a large stone up to the roof, because you wish to build the roof with it, but he is a weak man who is unable to do so. May he appoint someone else to carry the stone upstairs?

The answer is: yes, because a person like him would ordinarily be unable to do it.

Likewise, if you appoint him to sell a large quantity of goods and say to him, “Dispose of these goods during this season, and do not go beyond this season,” while they are so numerous that, if he were to handle them himself, the season would end before they could be sold—then he may appoint another. This is because when the principal says, “Sell these during this season,” while they are numerous goods and he knows that the agent cannot sell them alone, this means that he has authorized him to appoint someone else. Thus, the authorization is understood from the circumstances.

If someone were to ask, “How have you permitted him to appoint another in the latter two cases?” We say: because, although the principal did not expressly authorize it, it is regarded as customarily authorized. Everyone knows that if you say to an eminent man, “So-and-so, buy fodder for the cow every day,” it is understood that he will not buy it himself. And everyone knows that if you say to the agent, “Dispose of this merchandise during this season,” when the season is ten days long and the merchandise is plentiful, what is meant is that he should dispose of it himself or through his own agent.

In reality, these two cases fall under his statement, “unless authority is granted to him.” However, since the scholars mentioned them separately, we say: the first case is one in which authority is granted to him expressly, whereas in the second and third cases, authority has been granted to him by customary understanding.

His statement, “Agency is a non-binding contract”: it is non-binding from the legal-ruling perspective,