וְדָרַשְׁתָּ֧ וְחָקַרְתָּ֧ וְשָׁאַלְתָּ֖ הֵיטֵ֑ב וְהִנֵּ֤ה אֱמֶת֙ נָכ֣וֹן הַדָּבָ֔ר נֶעֶשְׂתָ֛ה הַתּוֹעֵבָ֥ה הַזֹּ֖את בְּקִרְבֶּֽךָ׃
און װעסט נאָכזוכן און אױספֿאָרשן און גוט נאָכפֿרעגן, ערשט די זאַך איז אמת ריכטיק, די דאָזיקע אומװערדיקײט איז געטאָן געװאָרן צװישן דיר,
Tze'enah Ure'enah
“You shall investigate and inquire” [13:15]. The verse shows us that one should properly question the witnesses. One should not quickly kill a person because of witnesses, but one should first ask the witnesses in which sabbatical cycle, what day of the month, what day and what hour of the day, in what place, and type of garment was he wearing white or red.14Bahya, Deuteronomy, 13:15.
Rashi
ודרשת וחקרת ושאלת היטב THEN SHALT THOU INQUIRE, AND MAKE SEARCH, AND ASK DILIGENTLY — From here — from the variety of expressions denoting inquiry in this verse — they (the Rabbis) derived the law of investigating capital cases by means of seven investigations” (referring to date, time and place). in the following manner: here (in our verse) there occur three expressions relating to inquiry, viz., ודרשת, וחקרת and היטב — the expression ושאלת does not come into account, because from it they derived בדיקות, the examination referring to accompanying circumstances, — and in another passage (Deuteronomy 19:18) it states, “and the judges shall enquire diligently (ודרשו השופטים היטב)”, and still in another passage (Deuteronomy 17:40) it states, “and thou shalt inquire diligently (ודרשת היטב)" — thus altogether seven expressions. — And although they are used in connection with different cases they learned by way of analogy (ג"ש) of the term היטב used here and in the passages quoted that it is intended to apply what is stated in one case to the others also (Sanhedrin 40a; cf. Sifrei Devarim 93:6).
Ramban
AND THOU SHALT INQUIRE, AND MAKE SEARCH, AND ASK DILIGENTLY. The nature of “inquiry” and “making search” [with which the judges are to test witnesses] are explained in the words of our Rabbis.176Sanhedrin 40a. Now Scripture mentions these investigations [here] in the case of an apostate city,177Literally: “a city [whose inhabitants were] led astray” after the idols. and also in the case of an idol-worshipper,178Further, 17:4. but it does not mention them in the case of the false prophet or the inciter, because the prophet publicizes himself with his signs and wonders, and in the case of the inciter Scripture addresses itself to the incited party: but thou shalt surely kill him,179Above, Verse 10. and he [the incited party, is the one] who knows and bears witness, just as is stated, neither shalt thou spare, neither shalt thou conceal him.180Ibid., Verse 9. Thus, Scripture need not enjoin diligent inquiry and testing of witnesses because the facts are well known to those charged with administering the penalty; the public in the case of a false prophet, and the victim in the case of the inciter. But in the case of an apostate city177Literally: “a city [whose inhabitants were] led astray” after the idols. and of an idol worshipper, which are deeds that reach us by means of report, Scripture mentions, with reference to them, inquiry and investigation [of the witnesses]. It was unnecessary to state this about the others liable to death because it is known by means of a kal vachomer.181A form of reasoning from “a minor” to “a major” matter. See Vol. II, p. 133, Note 208. Here it would apply as follows: If in those sins that bear less severe punishment [beheading in the case of an apostate city, etc.] the Torah requires “inquiry” and “investigation” of the witnesses, they are surely required in cases where the punishment is more severe, such as stoning. See Sanhedrin 40b. He states in the case of plotting witnesses, and the judges shall inquire diligently,182Further, 19:18. because it cannot be determined which of the two conflicting groups of witnesses is telling the truth except after considerable investigation. Concerning the law, all cases are deduced from each other by means of a similarity of Scriptural expressions. And from all the combined expressions we derive the principle that we are to test the witnesses with seven inquiries,183“In which Sabbatical seven-year period? In what year? In what month? On what date of the month? On what day [of the week]? In what hour? In what place?” (Sanhedrin 40a). Time and place are thus of the essence of the testimony. See the following note. and examinations.184The “investigations” related to matters incidental to the crime, such as how the victim was dressed. In the case of “the seven inquiries” (see preceding note) if one of the witnesses said “I do not know,” their testimony becomes invalid. But in the examinations, even if both did not know, their evidence was still valid. However, if they contradicted each other in examinations, their evidence was invalid. The number of investigatory questions is unlimited. In fact, “the more a judge examines the evidence, the more he is deserving of praise” (ibid.).