Where does the text say that?
Deu 17:18 And it shall be, when he sitteth upon the throne of his kingdom, that he shall write him a copy of this law in a book out of [that which is] before the priests the Levites:
Deu 28:58 If thou wilt not observe to do all the words of this law that are written in this book, that thou mayest fear this glorious and fearful name, THE LORD THY GOD;
Deu 28:61 Also every sickness, and every plague, which [is] not written in the book of this law, them will the LORD bring upon thee, until thou be destroyed.
Deu 29:21 And the LORD shall separate him unto evil out of all the tribes of Israel, according to all the curses of the covenant that are written in this book of the law:
Deu 30:10 If thou shalt hearken unto the voice of the LORD thy God, to keep his commandments and his statutes which are written in this book of the law, [and] if thou turn unto the LORD thy God with all thine heart, and with all thy soul.
Deu 31:24 And it came to pass, when Moses had made an end of writing the words of this law in a book, until they were finished,
Deu 31:26 Take this book of the law, and put it in the side of the ark of the covenant of the LORD your God, that it may be there for a witness against thee.
Jos 1:8 This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night, that thou mayest observe to do according to all that is written therein: for then thou shalt make thy way prosperous, and then thou shalt have good success.
Jos 8:31 As Moses the servant of the LORD commanded the children of Israel, as it is written in the book of the law of Moses, an altar of whole stones, over which no man hath lift up [any] iron: and they offered thereon burnt offerings unto the LORD, and sacrificed peace offerings.
Jos 8:34 And afterward he read all the words of the law, the blessings and cursings, according to all that is written in the book of the law.
Jos 23:6 Be ye therefore very courageous to keep and to do all that is written in the book of the law of Moses, that ye turn not aside therefrom [to] the right hand or [to] the left;
Jos 24:26 And Joshua wrote these words in the book of the law of God, and took a great stone, and set it up there under an oak, that [was] by the sanctuary of the LORD.
2Ki 14:6 But the children of the murderers he slew not: according unto that which is written in the book of the law of Moses, wherein the LORD commanded, saying, The fathers shall not be put to death for the children, nor the children be put to death for the fathers; but every man shall be put to death for his own sin.
2Ki 22:8 And Hilkiah the high priest said unto Shaphan the scribe, I have found the book of the law in the house of the LORD. And Hilkiah gave the book to Shaphan, and he read it.
2Ki 22:11 And it came to pass, when the king had heard the words of the book of the law, that he rent his clothes.
2Ki 23:24 Moreover the [workers with] familiar spirits, and the wizards, and the images, and the idols, and all the abominations that were spied in the land of Judah and in Jerusalem, did Josiah put away, that he might perform the words of the law which were written in the book that Hilkiah the priest found in the house of the LORD.
2Ch 17:9 And they taught in Judah, and [had] the book of the law of the LORD with them, and went about throughout all the cities of Judah, and taught the people.
2Ch 25:4 But he slew not their children, but [did] as [it is] written in the law in the book of Moses, where the LORD commanded, saying, The fathers shall not die for the children, neither shall the children die for the fathers, but every man shall die for his own sin.
2Ch 34:14 And when they brought out the money that was brought into the house of the LORD, Hilkiah the priest found a book of the law of the LORD [given] by Moses.
2Ch 34:15 And Hilkiah answered and said to Shaphan the scribe, I have found the book of the law in the house of the LORD. And Hilkiah delivered the book to Shaphan.
Neh 8:1 And all the people gathered themselves together as one man into the street that [was] before the water gate; and they spake unto Ezra the scribe to bring the book of the law of Moses, which the LORD had commanded to Israel.
Neh 8:3 And he read therein before the street that [was] before the water gate from the morning until midday, before the men and the women, and those that could understand; and the ears of all the people [were attentive] unto the book of the law.
Neh 8:8 So they read in the book in the law of God distinctly, and gave the sense, and caused [them] to understand the reading.
Neh 8:18 Also day by day, from the first day unto the last day, he read in the book of the law of God. And they kept the feast seven days; and on the eighth day [was] a solemn assembly, according unto the manner.
Neh 9:3 And they stood up in their place, and read in the book of the law of the LORD their God [one] fourth part of the day; and [another] fourth part they confessed, and worshipped the LORD their God.
For starters.
And then, the thing on Mount Sinai is the premise for the Torah.