כִּֽי־יִמָּצֵ֤א בְקִרְבְּךָ֙ בְּאַחַ֣ד שְׁעָרֶ֔יךָ אֲשֶׁר־יְהֹוָ֥ה אֱלֹהֶ֖יךָ נֹתֵ֣ן לָ֑ךְ אִ֣ישׁ אוֹ־אִשָּׁ֗ה אֲשֶׁ֨ר יַעֲשֶׂ֧ה אֶת־הָרַ֛ע בְּעֵינֵ֥י יְהֹוָה־אֱלֹהֶ֖יךָ לַעֲבֹ֥ר בְּרִיתֽוֹ׃
If there is found among you, in one of the settlements that the Eternal your God is giving you, a man or woman who has affronted the Eternal your God and transgressed the covenant—
Torah Temimah points to Sifrei Devarim.
כי ימצא. ולהלן הוא אומר (פ׳ ו׳) על פי שנים עדים וגו׳, זה בנה אב, שכל מקום שנאמר ימצא – בשנים ובשלשה עדים הכתוב מדבר.
English: “If there is found.” And later it says (verse 6) “on the testimony of two witnesses…” — this establishes a general principle: wherever Scripture says “is found,” it speaks of two or three witnesses.
The word “yimatzei” is treated as a binyan av requiring multiple witnesses for any capital or corporal procedure introduced by that language.
Binyan av (one of the 13 middot of Rabbi Yishmael). The occurrence of “yimatzei” together with the explicit requirement of two witnesses becomes the prototype for all similar expressions.
Any legal procedure whose biblical introduction uses the verb “yimatzei” requires the testimony of at least two witnesses.