(Devarim 13:14) "There have gone out men": and not women, and not minors. "men": not fewer than two.

"men of wickedness ("belial" [lit., "without a yoke"]): men who have cast from themselves the yoke of Heaven.

"from your midst": and not from a border city (i.e., one between Eretz Yisrael and the land of the nations).

"and they have turned away the inhabitants of their city": but not those of another city.

"saying": (We are hereby taught) that two witnesses and warning are required for each (of the cities). (Ibid. 15)

"And you shall inquire": of the Torah. "and you shall search out": from the witnesses. "and you shall ask": of the Talmud. Here (in respect to a man's serving idolatry) it is written (Ibid. 17:4) "And it be told to you, and you hear, and you inquire well," and elsewhere (in respect to scheming witnesses) (19:18) "And the judges inquire well" — "well" - "well" for an identity (gezeirah shavah.) (We are hereby taught) that he (the witness) undergoes seven cross-examinations (chakiroth).

Where do we derive (the need for) bedikoth (general examination of the facts, of lesser magnitude than chakiroth)? From (Ibid. 13:15) "and, behold, true and correct is the thing."

If in the end we include bedikoth, why chakiroth? With chakiroth, if one of them (the witnesses) said "I do not know," their testimony is invalidated. With bedikoth, if one of them, or even both of them said "I do not know," their testimony stands.

Both with chakiroth and bedikoth, if they refute each other, their testimony is invalidated.

"this abomination has been done in your midst": to include converts and freed slaves.