The Muslim should respect the mosques and keep them free of dirt and impurities, and anything that is not appropriate. In this hadith, the Prophet (blessings and peace of Allah be upon him) explains that spitting on the floor of the mosque is a sin, for which the doer deserves punishment from Allah (may He be exalted). The expiation for that sin is to bury it in the ground and cover it with earth. Whoever commits this bad deed and regrets it, and wants Allah to pardon him and erase this bad deed of his, should hasten to remove it from the mosque, by burying it if the mosque has an earthen floor, or by wiping it away and removing it, if the mosque is carpeted. Spitting in the mosque is a sin, because it is indicative of disrespect towards the houses of Allah (may He be glorified in exalted) which He has commanded are to be built and His name mentioned therein. Moreover, it is offensive to other worshippers. The worshipper may prostrate on it without realizing, and he may be disgusted if he sees it and find it repugnant. A report in al-Sahihayn explains that if someone cannot help but spit, he should spit to his left, or beneath his foot, or into the edge of his garment..