His statement, “It is disliked if the elevation is a cubit or more,” means that it is disliked for the imam to be a cubit or more above the follower.
The evidence for this is the hadith: “When a man leads people in prayer, let him not stand in a place higher than where they stand.” (1) However, this hadith is not strong enough to establish proof.
Those who cite it reconcile it with the authentic hadith recorded in al-Bukhari and Muslim—that the Messenger of Allah, peace and blessings be upon him, led them in prayer upon the minbar—by saying that the minbar generally does not exceed a cubit. Thus, this hadith is understood to refer to a considerable elevation. Yet the question remains as to estimating this by a cubit.
The answer is that the steps of the minbar generally do not exceed a cubit.
In summary, the author, may Allah have mercy on him, holds that there is nothing wrong with the imam being higher than the follower, except that it is disliked if the elevation is a cubit or more.
The second view is that it is not disliked for the imam to be elevated at all, because the hadith relied upon by the companions, may Allah have mercy on them, is weak, and a weak hadith cannot establish proof.
Some scholars have qualified this issue by stipulating that the imam should not be alone in his place. If someone is with him, then it is not disliked, even if the elevation exceeds a cubit, because the imam is not alone in his place. This is undoubtedly a sound view, for if the imam is alone in one place and the follower is in another, then where is the congregational prayer and the gathering together?