What do scholars mean when they say about the Quran "to Him it will return"?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

By "to Him it will return", the Righteous Predecessors meant that the Quran began from Allaah The Almighty as His Sayings and to Him it will return.

Ibn Taymiyyah mentioned said: "The Quran is the uncreated Words of Allaah The Almighty and it is one of His Attributes. It began from Him as Sayings and to Him it will return; it will be taken away from the chests (of those who memorize it) and from the Masaahif (copies of the Quran), so that no verse or letter will remain in people's hearts. This is stated in many traditions" [End of quote]. 

Allaah Knows best.