In his final days, before parting from the nation, Moses performs a lasting historical act. He completes the physical writing of the Torah, transforming the sequence of divine revelation into a sealed, eternal book. The primary approach among commentators is that the Torah was given and written scroll by scroll over the forty years of wandering in the desert. Only now, on the day of his death, did Moses gather all the scrolls and sew them together into a single, unified book [תורה תמימה]. Although he had previously given a version of the text to the priests, it was not yet entirely finished [רמב״ן, הטור הארוך]. The core of this teaching centers on the Commandments, which form the foundation of instruction for the people [בכור שור]. Now, the writing is brought to its absolute and perfect conclusion [ביאור שטיינזלץ, אבן עזרא].
To reach this state of perfection, specific final elements had to be added. Most commentators agree that Moses now included his parting song, his final blessings to the tribes, the command to ascend the mountain, and the account of his own death, finishing the book to its very last words before the eyes of all Israel [רמב״ן, ספורנו, העמק דבר, רש״ר הירש, ביאור יש״ר]. Another perspective notes that this final addition included the Commandment to gather the nation, thereby finalizing all practical Commandments [שד״ל]. This completion carries deep legal and spiritual significance, as the book cannot truly be called a Torah unless it is perfectly whole, without a single missing letter [צרור המור]. By sealing the entire book before his death, Moses fixed the text for eternity, ensuring that from then on, no one could ever touch, add to, or subtract from it [רמב״ן, ביאור יש״ר].
The events of this final day also involved a profound miracle regarding the speed of the writing. Moses did not merely write one copy; he wrote twelve complete Torah scrolls, giving one to each of the tribes of Israel [שפתי כהן]. Because writing such a massive amount of text in a single day is humanly impossible, the holy words were completed almost on their own, mirroring the miracles of the creation of the world and the construction of the Tabernacle [צרור המור].
This supernatural writing process carried a crucial theological message for the Israelites. Moses worried that in the future, the people might argue that only the Ten Commandments were absolutely binding because they were written by the finger of God, while the rest of the text was simply written by a human being. The miraculous completion of the entire Torah in a single day proved to everyone that God was the true author of the whole book, and Moses was merely a channel for His words. To permanently cement this understanding, Moses immediately ordered that the completed scroll be placed beside the Ark of the Covenant. This placement served as a lasting witness that the ink-written scroll is equal in holiness and authority to the stone-carved tablets, both standing together as an eternal testimony for the nation [אלשיך].