Is it permissible to face away from the Qur'an during prayer?

It is disliked to stretch one's legs towards the Mus'haf, to turn one's back to it, or to step over it. The same applies to books of knowledge that contain Quranic verses, out of reverence for them. It is also disliked to throw it on the ground without need. Therefore, a worshipper should not leave the Mus'haf behind his back if it is possible to move it towards the Qibla, or to the right or left. Otherwise, there is no harm in it.