הלכה אויף ויקרא 26:1

The floor of the Court is paved with expensive stones. If one of the stones was detached, even if it is still in place it is invalid [as part of the Temple] and a Priest cannot perform Temple services while standing on it until it is reattached.

When performing the rite of "falling on the face", after the service, some fall on the face, some prostrate themselves. The latter is forbidden on a stone floor, except in the Temple of Jerusalem, as has been explained in the laws concerning Idolatry. [Even] a worthy person may not fall on his face unless he is conscious that he is a righteous man like Joshua.^*(Joshua 5:14) “And Joshua fell on his face to the earth, and did worship.” He should only incline his face somewhat, but not press it against the floor. It is permissible to recite the service of prayer in one spot and "fall upon the face" elsewhere.

The pillar forbidden by the Torah, is a building where everybody assembles, even to serve God therein is forbidden, for in such manner was idolatry worshiped; for, it is said: "Neither shalt thou set thee up a pillar" (Deut. 16.22). And, whosoever sets up a pillar is lashed. The same applies to a figured stone spoken of in the Torah, although one bows down to it for the sake of God, he is lashed; for, it is said: "Neither shall ye place any figured stone in your land, to bow down unto it" (Lev. 26.1), because such was the practice of idolaters, to deposit a stone before it, upon which to bow down to it; therefore, shall it not be so in the worship of God. But he is not lashed, unless he spread his hands and feet upon the stone, so that he be bodily lying on it, for such is the kind of bowing down spoken of in the Torah.⁸Sifre, Deut. 16; Megillah, 22a–b. C.