(ד) שְׁמַ֖ע יִשְׂרָאֵ֑ל יְהוָ֥ה אֱלֹהֵ֖ינוּ יְהוָ֥ה ׀ אֶחָֽד׃
(4) Hear, O Israel! The LORD is our God, the LORD alone.
(ח) וּקְשַׁרְתָּ֥ם לְא֖וֹת עַל־יָדֶ֑ךָ וְהָי֥וּ לְטֹטָפֹ֖ת בֵּ֥ין עֵינֶֽיךָ׃
(8) Bind them as a sign on your hand and let them serve as a symbol on your forehead;
(לח) וְזֶ֕ה אֲשֶׁ֥ר תַּעֲשֶׂ֖ה עַל־הַמִּזְבֵּ֑חַ כְּבָשִׂ֧ים בְּנֵֽי־שָׁנָ֛ה שְׁנַ֥יִם לַיּ֖וֹם תָּמִֽיד׃
(38) Now this is what you shall offer upon the altar: two yearling lambs each day, regularly.
(לט) אֶת־הַכֶּ֥בֶשׂ הָאֶחָ֖ד תַּעֲשֶׂ֣ה בַבֹּ֑קֶר וְאֵת֙ הַכֶּ֣בֶשׂ הַשֵּׁנִ֔י תַּעֲשֶׂ֖ה בֵּ֥ין הָעַרְבָּֽיִם׃
(39) You shall offer the one lamb in the morning, and you shall offer the other lamb at twilight.
(מה) וְשָׁ֣כַנְתִּ֔י בְּת֖וֹךְ בְּנֵ֣י יִשְׂרָאֵ֑ל וְהָיִ֥יתִי לָהֶ֖ם לֵאלֹהִֽים׃
(45) I will abide among the Israelites, and I will be their God.
תניא כוותיה דר' יוסי ברבי חנינא ותניא כוותיה דרבי יהושע בן לוי תניא כוותיה דרבי יוסי בר' חנינא אברהם תקן תפלת שחרית שנא' (בראשית יט, כז) וישכם אברהם בבקר אל המקום אשר עמד שם ואין עמידה אלא תפלה שנאמר (תהלים קו, ל) ויעמד פינחס ויפלל
The Gemara comments: It was taught in a baraita in accordance with the opinion of Rabbi Yosei, son of Rabbi Ḥanina, and it was taught in a baraita in accordance with the opinion of Rabbi Yehoshua ben Levi. The Gemara elaborates: It was taught in a baraita in accordance with the opinion of Rabbi Yosei, son of Rabbi Ḥanina: Abraham instituted the morning prayer, as it is stated when Abraham came to look out over Sodom the day after he had prayed on its behalf: “And Abraham rose early in the morning to the place where he had stood before the Lord” (Genesis 19:27), and from the context as well as the language utilized in the verse, the verb standing means nothing other than prayer, as this language is used to describe Pinehas’ prayer after the plague, as it is stated: “And Pinehas stood up and prayed and the plague ended” (Psalms 106:30). Clearly, Abraham was accustomed to stand in prayer in the morning.
יצחק תקן תפלת מנחה שנאמר (בראשית כד, סג) ויצא יצחק לשוח בשדה לפנות ערב ואין שיחה אלא תפלה שנאמר (תהלים קב, א) תפלה לעני כי יעטף ולפני ה' ישפוך שיחו
Isaac instituted the afternoon prayer service; as it is said, "And Isaac went out to meditate in the field at evening time" (Gen. xxiv. 63) — there is no "meditation" [sihah] that is not prayer; as it is said, "A prayer of the afflicted when he faints, and pours out his complaint [sihah] before the Lord" (Ps, cii. 1).