ושננתם. לְשׁוֹן חִדּוּד הוּא, שֶׁיִּהְיוּ מְחֻדָּדִים בְּפִיךָ, שֶׁאִם יִשְׁאָלְךָ אָדָם דָּבָר לֹא תְהֵא צָרִיךְ לְגַמְגֵּם בּוֹ אֶלָּא אֱמֹר לוֹ מִיָּד (ספרי; קידושין ל'): ושננתם AND THOU SHALT TEACH THEM DILIGENTLY — This word expresses the idea of being sharply impressed, the meaning being, that they should be impressed (familiar) in thy mouth, so that if a person asks you anything concerning them, you will not need to stammer (hesitate) about it, but tell him forthwith (Sifrei Devarim 34:1; Kiddushin 30a)
לבניך. אֵלּוּ הַתַּלְמִידִים, מָצִינוּ בְּכָל מָקוֹם שֶׁהַתַּלְמִידִים קְרוּייִם בָּנִים, שֶׁנֶּאֱמַר (דברים י"ד) בָּנִים אַתֶּם לַה' אֱלֹהֵיכֶם, וְאוֹמֵר (מלכים ב ב') בְּנֵי הַנְּבִיאִים אֲשֶׁר בֵּית אֵל, וְכֵן בְּחִזְקִיָּהוּ, שֶׁלִּמֵּד תּוֹרָה לְכָל יִשְׂרָאֵל, וּקְרָאָם בָּנִים שֶׁנֶּאֱמַר (דברי הימים ב' כ"ט) בָּנַי עַתָּה אַל תִּשָּׁלוּ. וּכְשֵׁם שֶׁהַתַּלְמִידִים קְרוּיִים בָּנִים (שֶׁנֶּאֱמַר בָּנִים אַתֶּם לַה' אֱלֹהֵיכֶם) כָּךְ הָרַב קָרוּי אָב, שֶׁנֶּאֱמַר (מלכים ב ב') אָבִי אָבִי רֶכֶב יִשְׂרָאֵל וְגוֹ' (ספרי): לבניך [AND THOU SHALT TEACH THEM DILIGENTLY] UNTO THY CHILDREN — These are the disciples. Everywhere do we find that disciples are termed בנים, as it is said, (Deuteronomy 14:1) “Ye are children (בנים) of the Lord your God”; and it says, (2 Kings 2:3), “The sons of (בני) the prophets who were in Bethel”. So. too, do we find in the case of Hezekiah that he taught Torah to all Israel and termed them בנים, as it is said, (II Chronicles 29:11), “My sons (בני) be not now negligent". And even as disciples are termed בנים, “children", so the teacher is termed אב, "father", as it is said, (2 Kings 2:12) that Elisha referred to his teacher Elijah by the words, "My father, my father, the chariot of Israel, etc." (Sifrei Devarim 34:4).
ודברת בם. שֶׁלֹּא יְהֵא עִקַּר דִּבּוּרְךָ אֶלָּא בָּם – עֲשֵׂם עִקָּר וְאַל תַּעֲשֵׂם טָפֵל (שם): ודברת בם AND THOU SHALT SPEAK OF THEM — i.e. that your principal topic of conversation should be only about them: make them the principal, and do not make them of secondary importance (Sifrei Devarim 34:6).
ובשכבך. יָכוֹל אֲפִלּוּ שָׁכַב בַּחֲצִי הַיּוֹם, תַּ"ל ובקומך, יָכוֹל אֲפִלּוּ עָמַד בַּחֲצִי הַלַּיְלָה, תַּ"ל בשבתך בביתך ובלכתך בדרך – דֶּרֶךְ אֶרֶץ דִּבְּרָה תוֹרָה, זְמַן שְׁכִיבָה וּזְמַן קִימָה (שם): ובשכבך AND WHEN THOU LIEST DOWN — One might think that this means: even if one lies down (retires to bed) in the middle of the day, and that ובקומך AND WHEN THOU RISEST UP means: even if you rise up in the middle of the night! It, however, states בשבתך בביתך ובלכתך בדרך WHEN THOU SITTEST IN THY HOUSE AND WHEN THOU WALKEST BY THE WAY: The Torah is thus speaking of the usual way of living, and this therefore means, the usual time of lying down and the usual time of rising up (cf. Sifrei Devarim 36:9).