Midrash sa Mga Awit 119:160: Bereshit Rabbah, Ein Yaakov (Glick Edition), Otzar Midrashim & Shemot Rabbah

Rabbi Yitzḥak began: “The beginning of Your word is truth…” (Psalms 119:160) – Rabbi Yitzḥak said: Right from the beginning of the creation of the world [it can be seen that] “the beginning of Your word is truth” – “in the beginning, God created.” “But My Lord God is truth” (Jeremiah 10:10),²⁸This verse shows that God is the epitome of truth, and it is fitting that He should establish this truth right at the beginning of the Torah. This truth is the unity of God, as the Midrash goes on to explain. “All Your righteous laws are eternal” (Psalms 119:160) – as each and every edict that You decree upon Your creations, they accept the judgment upon themselves and receive it faithfully, and no person can come and say that two authorities created the world:²⁹Other versions add: Or that two authorities gave the Torah. “God [Elohim] spoke [vaydaberu]” is not written here [in plural], but rather [in singular], “God spoke [vaydaber];”³⁰Although the word Elohim is grammatically a plural form, the Torah constantly uses singular verbs with it, proving that God is indeed one. “God [Elohim] said [vayomeru]” is not written here [in plural], but rather [in singular], “God said [vayomer]”; “In the beginning God created [bare’u]” is not written here [in plural], but rather [in singular], “God created [bara].”

The great Ulla expounded at the door of the prince of the exile: "What does the passage (Ps. 138, 4) All the kings of the earth will give thanks unto Thee, O Lord, when they hear the words of Thy mouth, mean? It is not said the word of Thy mouth, but the words of Thy mouth (in plural). At the time when the Holy One, praised be He, said (Ex. 20, 2) I am the Lord thy God. .... thou shall not make unto thyself, all the nations said: 'He is only instructing, concerning His Own honor. But as soon as He said (Ib., ib. 12) Honor thy father and thy mother, they went back and began to praise Him, even on the first commandments." Raba said: "We infer this from the following (Ps. 119, 160) The beginning of Thy word is truth. Is it only the beginning and not the end of the word? We must therefore say that it means from the end of Thy word it was recognized that even the beginning of Thy word is truth."

After that, entered ר and said before Him: "Master of the world! You should make Your world through me, for through me is said (Psalm 119:160) 'The beginning¹ראש beginning with a ר of Your word is truth,' and also I am at the start of Your name called Merciful²רחום beginning with a ר as well as healing.³רפואה beginning with a ר" The Holy Blessed One responded and said to it, "No." It said "why?" He said to it: "Since through you Israel will in the future begin to worship idolatry, as is written (Numbers 14:4) 'Let us appoint a head⁴ראש beginning with a ר and return to Egypt.'" And why is idolatry called a "head?" As is written (Daniel 2:38) "The form of the head was of gold.' Also, ר is in evil⁵רע beginning with a ר and the beginning of wickedness⁶רשע beginning with a ר. Immediately it left from before His presence with a disappointed soul.