Is it permissible to prostrate on something elevated, such as a pillow or a desk, while praying sitting, for one who is unable to prostrate on the ground?

If a worshiper is unable to prostrate on the ground, nodding with the head for prostration is sufficient, and the nod for prostration should be lower than for bowing. He is not obliged to prostrate on a cushion or a desk. If he nods for prostration, he has fulfilled what is legally required, as Allah Almighty says: "Allah does not burden a soul beyond its capacity," and His saying: "So fear Allah as much as you are able." Some scholars have disliked a worshiper prostrating on something he raises.