“Someone who turns away in prayer, either with his eyes or his heart, is like a man whom the king summons and seats before him: just when the king starts to call out his name and addresses him, the man turns from him right and left, and his heart turns away. And since his heart is not present, he understands nothing of what the king says to him. What should this man expect from the king in return? At the very least, should he not expect to leave the palace – rejected, cast out and beneath consideration?
This worshipper is in no wise equal to the one whose heart is present, turned in prayer towards God and so aware of the Grandeur of the One before whom he stands that his heart is filled with awe, his head inclines and he would be ashamed before his Lord to face anyone else, or turn away.
About these two prayers, as Hassan bin ‘Atiya said: ‘Two men may offer prayer shoulder to shoulder, and yet between their two prayers lies a gulf as [vast] as that separating Heaven from earth. This is because one of them has his heart turned towards God, while the other is forgetful and heedless.’
Extract: The Invocation of God; Ibn al-Qayyim al-Jawziyya; page 2