Was the command to Moses, peace be upon him, to take off his sandals, in the words of Allah Almighty: "Indeed, I am your Lord, so take off your sandals; you are in the sacred valley of Tuwa" (Taha/12), out of reverence for Allah or for the valley? And if it was out of reverence for Allah, then how is it permissible for a worshiper to stand in prayer wearing his sandals?

Moses, peace be upon him, removed his sandals in the sacred valley by Allah's command and as a specific part of his law. As for the law of our Prophet Muhammad, peace and blessings be upon him, it permits prayer with pure sandals and leather socks (khuff), and it is even a Sunnah (definition), due to the Prophet's saying: "Differ from the Jews, for they do not pray in their sandals." It is prescribed for a Muslim to inspect their sandals and khuff and remove any impurity from them before entering the mosque. If they are clean, prayer with them is permissible. If the mosque is carpeted, one may choose to remove them as a precaution to maintain the cleanliness of the mosque and the worshippers, or one may pray in them if they are clean. As for khuff, if a Muslim performs ablution while wearing them, they should not remove them but rather pray in them after ensuring their cleanliness, because removing them invalidates the ablution.