Absolutely none that is known of. They come from different language families.
- Sàbaid and Sabbath come from Hebrew שבת which seems only ever to have been a calendar or time reference.
- No one seems to know where sabaid comes from but it does not seem to have any semantic connection to the Sabbath, and nor is it plausible that it has a Semitic root. I can't find any similar word even in Irish, Old Irish or Welsh.
Good question as it raises an important point. Gaelic, like Old Irish, Old High German and Old English, but unlike any other language I know of, including Modern Irish, has two prepositions for 'with', to solve precisely this problem.
- Whenever you are 'with' someone on the same side, use le.
- Whenever you are 'with' someone on the opposite side, use ri.
I use the rule of thumb that whenever you are facing the other person, such as when you are talking 'with' them, use ri, so there does not have to be any animosity, it it just that you are on the opposite side of the discussion.
Note the exception, còmhla ri 'together with'.
Ri comes from Old Irish fri. (It is quite normal for f to appear or disappear for no good reason.)
In Irish they always use le so the ambiguity would exist. (Actually dictionaries say that fri/fré does exist and now means the same as le but I have never heard it.)
If anyone is interested. with is from the Germanic word meaning ri, but the German word for 'with', mit is from the Germanic for le.
Wiktionary notes that ri can mean against in some situations, so I can see how it can be used here. If you are fighting with someone, and that someone is on the opposing side, they're fighting against them.
If you're talking with someone, you're facing them, and against and opposite are often related terms in languages.