For the source text click/tap here: Shavuot 22
To download, click/tap here: PDF
If he said: On my oath I will not eat, and he ate foods that are inedible or drank liquids that are not potable, he is exempt. If he said: On my oath I will not eat, and then he atethe meat of unslaughtered carcasses or tereifot, repugnant creatures or creeping animals, he is liable.
And Rabbi Shimon deems him exempt, since he is already under oath from Mount Sinai not to eat them and an oath cannot take effect where another oath is in force. But if he said: It iskonam for my wife to derive benefit from me if I ate today, and he had eaten carcasses or tereifot, repugnant creatures or creeping animals, his wife is prohibited from deriving benefit from him.
We explore the possible reciprocity of the wife makes the oath
And the ascetic tendencies of the Ramban whether it might have been influenced by his disputation with the Dominicans.