In today’s daf (Yoma 77b) we encounter a fascinating psak which highlights the broad considerations at play when a posek renders a halachic decision.
As noted in the Gemara, any form of bathing in water is forbidden on Yom Kippur. However, we are then taught in a Beraita that if a person needs to pass through a stream of water to reach a particular location on Yom Kippur – such as to visit a parent or teacher – then doing so is not considered to ‘bathing’ in the fullest sense of the term and is justified in such a situation.
The question, however, is whether such a person may return back on Yom Kippur by wading through water, given the fact that they have now fulfilled their duty? Meaning, is passing through water totally permitted in all cases, or only partially permitted for certain situations?
We are told that Rava permitted the people of Avar Yemina to pass through water on Yom Kippur in order to guard their fruits which they owned on the other side of the water. And we are then informed that Rav Yosef permitted the people of Bei Tarbu to pass through water on Yom Kippur in order to attend a public Torah lecture which was being held in a location on the other side of the water.
In neither cases are we initially told that the people were permitted to return. But in the second case – and according to one version of the incident, after Rav Yosef explicitly instructed the people that they may not return through the water – Abaye granted permission to the people to do so, with his reason being that otherwise this would lead the people to stumble in the future (i.e. they would not come to such lectures in the future).
What all this suggests is that passing through water is only partially permitted for certain situations – which is why the Shulchan Aruch (OC 613:8) forbids those who traversed through water to guard their fruits on Yom Kippur to return through water on Yom Kippur.
But also, that poskim must also take a long-term view when paskening – which is why the Shulchan Aruch (OC 613:5) permits those who traversed through water to learn Torah on Yom Kippur to return through water on Yom Kippur. Because by permitting them to return, they were ultimately encouraging and enabling to come back next year.