1
שֶׁלֹּא לְהַעֲלִים עֵינָיו מִמֶּנָּה – שֶׁלֹּא נַעֲלִים עַיִן מֵאֲבֵדַת אַחֵינוּ (ב"מ כו ב), אֲבָל נִקָּחֶהָ וּנְשִׁיבָהּ אֵלָיו, וְעַל זֶה נֶאֱמַר (דברים כב ג) לֹא תוּכַל לְהִתְעַלֵּם. To not avoid his eyes from it: That we should not avoid our eye from the lost item of our brother (Bava Metzia 26b), but we [rather] take it and return it to him. And about this is it stated (Deuteronomy 22:3), “you may not ignore [it].”
2
כָּל עִנְיַן הַמִּצְוָה כָּתוּב בְּמִצְוַת עֲשֵׂה שֶׁלּוֹ (מצוה תקלח) שֶׁבְּסֵדֶר זֶה. The whole matter of this commandment is written in its [corresponding] positive commandment (Sefer HaChinukh 538) in this Order.