כי יסיתך. אֵין הֲסָתָה אֶלָּא גֵּרוּי, שֶׁנֶּאֱמַר (ש"מ כ"ו) אִם ה' הֱסִיתְךָ בִּי, אנסיטר"א בְּלַעַז, שֶׁמַּשִּׂיאוֹ לַעֲשׂוֹת כֵּן: כי יסיתך IF [THY BROTHER …] ENTICE THEE — The term יסת always denotes to “stir up”, “to incite”, as it is said, (I Samuel 26:19) ”If it be the Lord that hath stirred thee up (הסיתך) against me” (Sifrei Devarim 87:2); inciter in O. F., Engl, to incite — i.e. that he induces one to act thus.
אחיך. מֵאָב: אחיך THY BROTHER — means, thy brother on the father’s side (Sifrei Devarim 87:4).
אוֹ בן אמך. מֵאֵם: בן אמך THE SON OF THY MOTHER — i.e., thy brother on the mother’s side. (The meaning of the Hebrew words is: thy brother or the son of thy mother) (Sifrei Devarim 87:5).
חיקך. הַשּׁוֹכֶבֶת בְּחֵיקְךָ וּמְחֻקָּה בְּךָ, אפקיי"דא בְּלַעַז, וְכֵן (יחזקאל מ"ג), "וּמֵחֵיק הָאָרֶץ" – מִיסוֹד הַתָּקוּעַ בָּאָרֶץ: חיקך [OR THE WIFE OF] THY BOSOM — i.e. who lies on thy bosom and is attached (מחוקה) to you, affichee in O. F. Similar is the expression (Ezekiel 43:14) “and from the bottom (מחיק) upon the ground” — i.e. from the foundation that is sunk in the ground.
אשר כנפשך. זֶה אָבִיךָ, פֵּרֵשׁ לְךָ הַכָּתוּב אֶת הַחֲבִיבִין לְךָ, קַ"וָ לַאֲחֵרִים: אשר כנפשך [OR THY FELLOWMAN] WHO IS AS THINE OWN SOUL — Thus refers to thy father (Sifrei Devarim 87:11). Scripture specially mentions all those who are dear to you — that you must not consent unto them nor spare them (v. 9), how much the less should you consent unto others or spare them.
בסתר. דִּבֵּר הַכָּתוּב בַּהוֹוֶה, שֶׁאֵין דִּבְרֵי מֵסִית אֶלָּא בַּסֵּתֶר, וְכֵן שְׁלֹמֹה הוּא אוֹמֵר (משלי ז') "בְּנֶשֶׁף בְּעֶרֶב יוֹם בְּאִישׁוֹן לַיְלָה וַאֲפֵלָה": בסתר [IF THY BROTHER ENTICE THEE] SECRETLY — Scripture speaks of what usually occurs (but does not intend to exclude one who entices people publicly), for usually the words of the enticer are spoken in secret. Similarly does Solomon say of the strange woman that she practises her art of seduction (Proverbs 7:9) “In the twilight, in the evening of the day, in the blackness of night and the darkness” (Sifrei Devarim 87:12).
אשר לא ידעת אתה ואבתיך. דָּבָר זֶה גְּנַאי גָּדוֹל הוּא לְךָ – שֶׁאַף הָאֻמּוֹת אֵין מַנִּיחִין מַה שֶּׁמָּסְרוּ לָהֶם אֲבוֹתֵיהֶם, וְזֶה אוֹמֵר לְךָ עֲזֹב מַה שֶּׁמָּסְרוּ לְךָ אֲבוֹתֶיךָ (ספרי): אשר לא ידעת אתה ואבתיך [LET US GO AND SERVE OTHER GODS] WHICH THOU HAST NOT KNOWN, THOU, NOR THY FATHERS — This would be a great disgrace for you: for not even the heathen nations abandon that which their fathers have handed down to them, and this man says to you, “Abandon what thy fathers have handed down to you”! (Sifrei Devarim 87:13).