(9) אַתֶּם נִצָּבִים הַיּוֹם כֻּלְּכֶם לִפְנֵי יי אֱלֹקֵיכֶם רָאשֵׁיכֶם שִׁבְטֵיכֶם זִקְנֵיכֶם וְשֹׁטְרֵיכֶם כֹּל אִישׁ יִשְׂרָאֵל: (01) טַפְּכֶם נְשֵׁיכֶם וְגֵרְךָ אֲשֶׁר בְּקֶרֶב מַחֲנֶיךָ מֵחֹטֵב עֵצֶיךָ עַד שֹׁאֵב מֵימֶיךָ: (11) לְעָבְרְךָ בִּבְרִית יי אֱלֹקֶיךָ וּבְאָלָתוֹ אֲשֶׁר יי אֱלֹקֶיךָ כֹּרֵת עִמְּךָ הַיּוֹם: (21) לְמַעַן הָקִים־אֹתְךָ הַיּוֹם ׀ לוֹ לְעָם וְהוּא יִהְיֶה־לְּךָ לֵאלֹקִים כַּאֲשֶׁר דִּבֶּר־לָךְ וְכַאֲשֶׁר נִשְׁבַּע לַאֲבֹתֶיךָ לְאַבְרָהָם לְיִצְחָק וּלְיַעֲקֹב: (31) וְלֹא אִתְּכֶם לְבַדְּכֶם אָנֹכִי כֹּרֵת אֶת־הַבְּרִית הַזֹּאת וְאֶת־הָאָלָה הַזֹּאת:(41) כִּי אֶת־אֲשֶׁר יֶשְׁנוֹ פֹּה עִמָּנוּ עֹמֵד הַיּוֹם לִפְנֵי יי אֱלֹקֵינוּ וְאֵת אֲשֶׁר אֵינֶנּוּ פֹּה עִמָּנוּ הַיּוֹם:
(9) You stand this day, all of you, before Adonai your God—your tribal heads, your elders and your officials, all the men of Israel, (10) your children, your wives, even the stranger within your camp, from woodchopper to water drawer— (11) to enter into the covenant of Adonai your God, which Adonai your God is concluding with you this day, with its sanctions; (12) to the end that Adonai may establish you this day as Adonai's people and be your God, as Adonai promised you and as Adonai swore to your fathers, Abraham, Isaac, and Jacob. (13) I make this covenant, with its sanctions, not with you alone, (14) but both with those who are standing here with us this day before Adonai our God and with those who are not with us here this day.
Chizkuni (Hezekiah ben Manoah, France, 1250-1310)
"You stand this day, all of you" -- all of you regardless of your social standing in the community are equally standing facing God, in order to enter into the new covenant... "woodchopper", i.e. male servants; “water drawer", i.e. female servants... from the leader of the wood choppers to the most lowly of the water drawers.
Sforno (Ovadia ben Jacob Sforno, Italy, 1475-1550)
"To enter into the covenant" - you are all arranged in this order in order to signal your acceptance of the forthcoming covenant. It is clear from Moses’ addressing all the assembled, that they were of one mind at the time, all willing and eager to accept the covenant.
ibn Ezra (Abraham ben Meir Ibn Ezra, Spain, 1089-1167)
"Not with you alone" - but rather, with you, and with those who shall come after you: your children, and your children’s children.
Sforno (Ovadia ben Jacob Sforno, Italy, 1475-1550)
"Those who are not here this day" - a reference to future, as yet unborn generations. You will therefore have to explain to these unborn generations in due course that you yourselves only received this land on the understanding that subsequent generations of Jews would remain loyal to the terms of your acceptance. They will continue to inherit the land from you only on that basis.
Rav Aḥa, the son of Rava, said to Rav Ashi: What about converts?... Rav Ashi said to him: Even though they themselves were not at Mount Sinai, their guardian angels were present, as it is written: “It is not with you alone that I make this covenant and this oath, but with he that stands here with us today before Adonai our God, and with he that is not here with us today” (Deuteronomy 29:13–14), and this includes converts.
(ט) וְגֵ֖ר לֹ֣א תִלְחָ֑ץ וְאַתֶּ֗ם יְדַעְתֶּם֙ אֶת־נֶ֣פֶשׁ הַגֵּ֔ר כִּֽי־גֵרִ֥ים הֱיִיתֶ֖ם בְּאֶ֥רֶץ מִצְרָֽיִם׃
You shall not oppress a stranger, for you know the soul of the stranger, having yourselves been strangers in the land of Egypt.
Rashi (Solomon ben Isaac, France, 1040-1105)
"For you know the soul of the stranger" - how hard it is for him when people oppress him. "Having yourselves been strangers in the land of Egypt" - due to your personal experience of such a status, you, better than anyone else, know that seeing that the oppression of strangers is a great wrong, the punishment for violating such a commandment is equally harsh.
Chizkuni (Hezekiah ben Manoah, France, 1250-1310)
It is repeated here as he is also one of the sections of society that is likely to be taken advantage of as they have no one to stand up on their behalf. It is easy to get away with taking advantage of them.