Aliya Summary: G‑d commanded Moshe to enter the Tabernacle together with Joshua. G‑d appeared to them both and informed them that a time will come when the Israelites will abandon G‑d and stray after alien gods. At that time, G‑d will hide His countenance from the nation, and they will be subjected to much evils and troubles. Therefore, G‑d says, “Write for yourselves this song, and teach it to the Children of Israel. Place it into their mouths, in order that this song will be for Me as a witness…” This ‘song’ is narrated in next week’s Torah reading.
We are commanded to write “The Song” (namely the whole Torah), to teach it to the people, so that it should serve as a testament among the People of Israel. This is mitzva #613, to write a Sefer Torah. Our Sages include in this mitzva the significance of acquiring books from which to learn Torah. Since the Torah itself specifies that the “purpose” of writing a Torah scroll is to learn and teach from it, then writing, buying, acquiring all learning texts would be in the spirit of this mitzva.