What is the unequivocal Book mentioned in the verse: "This is the Book about which there is no doubt," and was the Qur’an revealed to be preserved in bosoms and not in the form of a book, and did Allah Almighty command His Prophet to preserve it in a book?

The Almighty's saying: "(This is the Book about which there is no doubt, a guidance for those conscious of Allah)" (2:2) refers to the Qur’an, by consensus of the scholars. The apparent problem of the Qur’an being called a "Book" before its compilation can be answered in three ways:

1. The root word (kataba) indicates gathering and joining, whether it is the gathering of letters in writing or the gathering of words and phrases. 2. The intention behind "writing" (al-katb) is that the Qur’an gathered meanings, rulings, lessons, and verses, and that it encompassed the purposes of the revealed scriptures. 3. The designation "Book" refers to what was actually written down from it, as portions of the Qur’an were written as they were revealed. The Prophet, peace and blessings be upon him, appointed scribes for revelation, and this indicates its future complete compilation.