ופן תשא עיניך. לְהִסְתַּכֵּל בַּדָּבָר וְלָתֵת לֵב לִטְעוֹת אַחֲרֵיהֶם: ופן תשא עיניך AND LEST THOU LIFT UP THINE EYES to ponder on the matter, and to set your heart to go astray after them.
אשר חלק ה'. לְהָאִיר לָהֶם (מגילה ט'); דָּ"אַ לֶאֱלוֹהוֹת, לֹא מְנָעָן מִלִּטְעוֹת אַחֲרֵיהֶם אֶלָּא הֶחֱלִיקָם בְּדִבְרֵי הַבְלֵיהֶם לְטָרְדָם מִן הָעוֹלָם, וְכֵן הוּא אוֹמֵר (תהלים ל"ו) "כִּי הֶחֱלִיק אֵלָיו בְּעֵינָיו לִמְצֹא עֲוֹנוֹ לִשְׂנֹא" (עבודה זרה נ"ה): אשר חלק ה׳ WHICH THE LORD ASSIGNED to give light to them (to all peoples) (Megillah 9b). — Another explanation: which God assigned to them as deities; He did not prevent them from going astray after them, but He allowed them to err (to slip) through vain speculations, in order to drive them out from the world. Similarly it states, (Psalms 36:3) "He (God) made him err (slip) through his eyes (i.e. through what his eyes behold) until his iniquity be found and he be hated” (Avodah Zarah 55a).