Hurayrah, in which he reports that the Prophet, peace and blessings be upon him, said: “When one of you prostrates, let him not go down as a camel goes down.” (1) The Messenger, peace and blessings be upon him, forbade a man from going down as a camel goes down. When a camel kneels, it puts forward its forelegs, bringing its front down before its rear, as can be observed.
Some scholars have supposed that the meaning of his words, “let him not go down as a camel goes down,” is: let him not go down upon that on which the camel goes down—that is, he forbade a person from going down upon his knees; accordingly, he should put his hands down first. But there is a clear difference between the two wordings. The prohibition in the phrase, “as a camel goes down,” is a prohibition of the manner, because the particle ka- denotes comparison. Had the wording been, “let him not go down upon that on which the camel goes down,” it would have been a prohibition concerning that upon which one prostrates. Accordingly, one should not prostrate upon his knees, since the camel goes down upon its knees; and thus he should put his hands down first.
As for this being required by rational consideration: the body’s natural manner is to descend gradually, just as it rises from the ground gradually. If it descends gradually, its lower part comes down before its upper part; and if it rises gradually, its upper part rises before its lower part. Thus, the view held by the majority of the scholars accords with both the transmitted evidence and natural disposition. Nevertheless, if a person is heavy, ill, or has a condition in his knees that makes prostrating upon them difficult, then there is no harm in putting the hands down first. The prohibition applies where no reason calling for this exists; but if there is a reason calling for it, then there is no harm in doing so, for the foundation of the Islamic religion, and all praise is due to Allah