Based on yesterday's halacha (Jewish law), there's a very big chiluk (distinction) that comes out. Yesterday we discussed a brit milah (circumcision) that was postponed. We said that you cannot do brit milah on Thursday or Friday, and in that case you would have to wait until Sunday.
Based on this, a rule comes out: anything that may bring a chilul Shabbat (break the Shabbat) is assur (not allowed) to do on Thursday or Friday, because it's not just the brit milah. Brit milah was one example. It's actually the base of the brit milah is the source of the brit milah is the person who travels on Thursday and Friday, and therefore you see that it has nothing to do with the brit milah. It's not a brit milah problem. It's actually anything that may cause a person to have to do a chilul Shabbat on Thursday or Friday. To do a chilul Shabbat, a person would be assur to initiate that thing that could bring about a chilul Shabbat on a Thursday or Friday.
Hacham Ovadia is discussing a surgery that is not a life-threatening surgery. Sometimes things could become complicated, because anytime you do a surgery, it could get infected; it could get complicated if you do it a day or two later. Therefore, the question is: are you allowed to schedule a surgery on a Thursday or Friday? Hacham Ovadia says, based on what we said, it's assur. You're not allowed to schedule a surgery. An emergency surgery is a different story, or if there's a really good, strong reason—it's a better doctor, etc.—and you only do it on Thursday, that's a different story. But if it's totally elective, you could wait until Sunday, Monday, or Tuesday, then one should do that and not get any kind of surgery before Shabbat, because of what we just said: any three days before Shabbat is considered like somebody is traveling; it would be assur.
He goes even deeper in the following case. Many times a woman has to schedule giving birth. He says there are two reasons not to schedule a C-section or a delivery on a Thursday. Why? Number one, he says it's true that after the birth, a lady is considered—and you could break the Shabbat in case there are any complications, of course—but what's going to happen if they do a C-section on a Thursday? They're going to need to do the brit milah on the following Thursday. You're back into the problem of the brit milah. He says, now you schedule a birth: if it's a boy, you're going to have to do brit milah on Thursday. We said you don't do brit milah on Thursday unless it's time and it's going to be time, so therefore you do it on Thursday if you could do it on Shabbat and it's on time; you could do it on Thursday, of course. Why schedule it in such a way that you may enter the three days before Shabbat? And therefore he says it's better if you do it on Thursday. It's possible; again, many times it is scheduled. If it's scheduled, you cannot schedule it on Thursday or Friday. You have to schedule a different day, not only because of the lady's health but also because now you are pushing to have a brit milah before Shabbat, and that is better not to do. Therefore, it's better to schedule it for a time that is not Thursday or Friday.