Luke 14:5

‘And he said to them, “Which of you shall have an ass or an ox fallen into a well, and will not straightway draw him up on a sabbath day?”

Then Jesus turned to those who were watching Him through narrowed eyes and asked them which of them, if a domestic animal had fallen into a pit on the Sabbath, would not lift it out. Strictly speaking they should only have done so if its life was being threatened, but in practise all knew what they would do. No decent person could leave an animal struggling in a pit. For like many today they were more caring for animals than for humans.

Note how the ‘falling' of the animal into the pit parallels the disease of a man whose skin was ‘falling' because of liquid under the skin.

Some leading MS (including p45, p75, B and W) have ‘son' instead of ‘ass'. It certainly makes the argument more powerful, and is textually strong. It is probably correct and strengthens the statement. No one would conceivably leave their own son, presumably a child, in a well when he had fallen down it. Even at Qumran the helping of a son out of such a situation was permitted on the Sabbath. But it was not the same at Qumran for an ox.