Someone for whatever reason was not able to eat Erev Tisha B'Av. It came shkia (sunset) and finally he was able to find time or the ability to eat. Is it better for him to eat then during Bein Hashmoshos and be able to fast then all of Tisha B'Av. Or better not to eat during Bein Hashmoshos and wait until the he gets into a situation where he feels he must eat even if it's on Tisha B'Av itself?

Essentially the question comes down to, is it better to do a "sofek issur" or a "v'dei issur in a situation of an ones"?

  • How does he know that a time will come when he must eat on Tisha B'Av? Maybe he will be able to make it through the day without needing to eat.
    – Daniel
    Jul 29, 2013 at 21:10
  • @Daniel Perhaps but if you've ever tried it before, it's quite difficult. I once had to do it before a medical procedure (drank one day before and then the day of had to fast -- after the procedure around noon time I was already starving and very weak...) That's why I pointed out what the question "boils down to" and if there is a proof anywhere for that point. This is just a theoretical (but somewhat practical as well) example
    – Yehoshua
    Jul 29, 2013 at 21:18
  • Forbidden to eat or do a Malacho on arav shabboth since it is not known if it is night or not. Jul 30, 2013 at 4:04
  • @MoriDoweedhYa3gob - I disagree; during Bein Hashmashot you can do certain Rabbinic Melachot, as enumerated in במה מדליקין which we say say (learn) every Friday night in shul. Aug 7, 2013 at 9:34
  • @danny however tisha3 ba'ov is the same as Yom Kippur in all matters(except a few) and on 3arav Yom Kippur we don't eat bein hashamoshoth. Aug 7, 2013 at 16:49

1 Answer 1


Assuming there's a good chance that you would have to break your fast, I would be tempted to allow you to eat before nightfall - and then have you fast until Rabbeinu Tam so that - at least according to one opinion - you have fasted the entire fast.

However, were I to be a Rabbi, I would be hesitant to actually pasken this way; I wouldn't want people to do this on Yom Kipopur (and people tend to confuse the 2 fasts and/or transpose halachot from one to the other.)

Then again, you summarised your question as:

Essentially the question comes down to, is it better to do a "sofek issur" or a "v'dei issur in a situation of an ones"?

You now have to deal with 2 rules of halocho: אין ספק מוציא מידי וודאי as well as אונס רחמנא פטריה which both would indicate that you'd be better off not eating, and then - if and when the need arises - you are allowed to eat.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .