Genesis 34:25

And it was on the third day, when they were weak from the pain of their circumcision, two of the sons of Jakob, Shimeon and Levi, the brothers of Dinah, took each man his sword, and came upon the city, which was dwelling securely and killed every male.

בהיותם כואבים, according to normal reactions of people to such an operation, and according to the plain meaning of the text, the meaning is that they had been in pain during the first and second day after the circumcision, and they were now in even greater pain,

ויבואו על העיר, the people there felt perfectly safe, so that Shimon and Levi did not need to take any precautions. Whenever the word בטח occurs throughout Scriptures, it refers to the people feeling secure, unworried, just as in this verse.

ויהרגו כל זכר, these men had not circumcised themselves in order to become Jews and embrace monotheism but only in order to lay their hands on the vast possessions of the family of Yaakov, as their leaders Chamor and Shechem had promised them.

ויהי ביום השלישי בהיותם כואבים, this was because the pains are strongest on the third day after the circumcision. In view of this the sages permitted bathing the child with hot water on the Sabbath after the circumcision, if it coincided with being the third day after the operation.(Shabbat 134). Even hot water boiled on the Sabbath itself is permissible to be used for this when there is no other, as the potential danger to the life of the infant overrides the Sabbath legislation not to boil anything on that day.

ויקחו שני בני יעקב, in this instance, Shimon and Levi, although all the brothers were in complete agreement of what was being planned. We know this from verse 13 ויענו בני יעקב במרמה, “the sons of Yaakov responded, deceitfully.” When it came to carrying out their plan, the other brothers were afraid and did not risk their lives in that undertaking. Only Shimon and Levi considered the fate of their sister as paramount. אחי דינה; the Torah accords them full points for considering themselves as the brothers of Dinah par excellence, although at least four more of the brothers were Dinah’s brothers both from the father and from the mother.

בטח, they were feeling as secure as if they were numerous and not 2 against a whole town.

ויהי ביום השלישי בהייותם כואבים, “it was on the third day (after circumcision) when they were all in pain, etc.” it is difficult to understand why the brothers had insisted that all these people circumcise themselves when they had meant to kill them anyways. Why did they have to resort to such deceit? Our verse may provide the answer by reporting that on that day the men of Sh’chem regretted having circumcised themselves. It was on account of that Shimon and Levi killed them. There had been no intent to kill them when they demanded that they circumcise themselves if they wanted to become members of the clan of Semites. Their act of circumcision was perceived by them as an initiation rite. Also, there is no reason to assume that they should have been in greater pain on the third day than on the previous two days. In fact, it is likely that they had not been able to circumcise themselves all on a single day, and the third day that the Torah speaks of was the day when these circumcisions were completed. This is why Shimon and Levi did not take their swords until the third day.