The twenty-first perek of Massekhet Shabbat deals with a topic that has already been introduced earlier in the tractate, the laws of set-aside [muktze] – items that are set aside and may not be handled on Shabbat – though from a fresh perspective. Here, too, the discussion is not about different items that are set aside, but about particular categories of items that all agree may not be moved on Shabbat because they are not utensils and are not fit to be handled. It was clear to the Sages that such items may not be handled directly; the discussion in this chapter primarily addresses the question of whether it is permitted to move these types of set-aside items, and set-aside items generally, through another object or for the sake of something else.
The first example offered in the Mishna on today’s daf teaches:
A person may take his son in his hands on Shabbat, and even though there is a stone, which is a set-aside item, in the child’s hand, it is not prohibited to pick up the child.
The Gemara discusses why the father may pick up his son even though the child is holding a stone, assuming at first that it is because the stone is considered to be batel – negated – in the context of the child. This position is rejected, however, and another possibility is suggested.
The Sages of the school of Rabbi Yannai say: You cannot infer from this Mishna that the stone is negated and therefore it is permitted to move it. Rather, the Mishna is referring to a baby who has longings for his father.
It is permitted for the father to move the stone because if the father does not lift him, the baby might take ill. Some commentaries explain that the baby longs for the stone and would cry if his father would take it from him. Therefore, the Sages permit the father to carry both of them (Tosefot Rid).