(ד) שְׁמַ֖ע יִשְׂרָאֵ֑ל יי אֱלֹקֵ֖ינוּ יי ׀ אֶחָֽד׃ (ה) וְאָ֣הַבְתָּ֔ אֵ֖ת יי אֱלֹקֶ֑יךָ בְּכָל־לְבָבְךָ֥ וּבְכָל־נַפְשְׁךָ֖ וּבְכָל־מְאֹדֶֽךָ׃ (ו) וְהָי֞וּ הַדְּבָרִ֣ים הָאֵ֗לֶּה אֲשֶׁ֨ר אָנֹכִ֧י מְצַוְּךָ֛ הַיּ֖וֹם עַל־לְבָבֶֽךָ׃ (ז) וְשִׁנַּנְתָּ֣ם לְבָנֶ֔יךָ וְדִבַּרְתָּ֖ בָּ֑ם בְּשִׁבְתְּךָ֤ בְּבֵיתֶ֙ךָ֙ וּבְלֶכְתְּךָ֣ בַדֶּ֔רֶךְ וּֽבְשָׁכְבְּךָ֖ וּבְקוּמֶֽךָ׃ (ח) וּקְשַׁרְתָּ֥ם לְא֖וֹת עַל־יָדֶ֑ךָ וְהָי֥וּ לְטֹטָפֹ֖ת בֵּ֥ין עֵינֶֽיךָ׃ (ט) וּכְתַבְתָּ֛ם עַל־מְזוּזֹ֥ת בֵּיתֶ֖ךָ וּבִשְׁעָרֶֽיךָ׃ (ס)
(4) Hear (and pay attention), O Israel! Adonai is our God, Adonai alone/is one. (5) You shall love Adonai your God with all your heart and with all your soul and with all your might. (6) Take to heart these commandments I give you this day. (7) Teach them to your children. Recite them when you stay at home and when you are away, when you lie down and when you get up. (8) Bind them as a sign on your hand and let them serve as a symbol on your forehead; (9) inscribe them on the doorposts of your house and on your gates.
Written down 645-600 BCE
Rabbi Hillel was asked to teach the entire Torah while standing on one foot. Rabbi Hillel stood on one foot and said, "What is hateful to you, don't do to your neighbor. Now go and learn."
Tractate Shabbat 31a
Rabbi Akiva was once asked, "What is the greatest principal in the Torah?" Rabbi Akiva answered, "v'ahavta l'reicha kamoacha, zeh klal gadol b'Torah." Love your neighbor as yourself is the greatest principal in the Torah.