Rabbi Hiyya that he had not witnessed Rabbi Judah the Prince accept upon himself the yoke of the Heaven by reciting the Shema. Rabbi Hiyya replied to Rav that in the moment that Rabbi Judah the Prince passed his hand to cover his eyes to recite, "Hear, O Israel, the Lord our God, the Lord is One," he accepted upon himself the yoke of the kingdom of Heaven. Rabbi Joshua ben Korhah taught that in the Shema, Jews recite the words of ("Here, O Israel . . . ," Shema Yisrael . . .) before those of ("And it shall come to pass . . . ," VeHaya im Shamoa . . .) so that one first accepts the yoke of Heaven by proclaiming the Unity of God and then accepts the yoke of the commandments by saying the words, "If you shall diligently heed all My commandments." Jews recite the words of ("And it shall come to pass . . . ," VeHaya im Shamoa . . .) before those of ("And the Lord said . . . ," VaYomer . . .) because is applicable both in the day and the night (since it mentions all the commandments), whereas is applicable only in the day (since it mentions only the precept of fringes, tzitzit, which is not obligatory by night). The Mishnah taught that the absence of one of the two portions of scripture in the mezuzah — and — invalidates the other, and indeed even one imperfect letter can invalidates the whole. The Mishnah taught that the absence of one of the four portions of scripture in the Tefillin — and 11–16 and and — invalidates the others, and indeed even one imperfect letter can invalidate the whole. Reading , "Hear, O Israel, the Lord our God, the Lord is One," the Rabbis taught that God told Israel that all that God had created, God created in pairs: heaven and earth, sun and moon, Adam and Eve, this world and the World To Come. But God's Glory is One and Unique in the world. Rabbi Isaac linked the words "the Lord our God" in with , "The Lord is my portion, says my soul." Rabbi Isaac compared this to a king who entered a province with his generals, officials, and governors. Some of the citizens of the province chose a general as their patron, others an official,