Piety means fearing Allah and being heedful of Him in all deeds, and abiding by His commands, prohibitions, and rulings in all aspects of life. The Muslim must adopt piety and must seek to attain it. Allah Almighty commended piety and the pious people in the Qur’an. In this Hadīth, the Tābi‘i Abu Salamah ibn ‘Abdur-Rahmān ibn ‘Awf reports that ‘Abdur-Rahmān ibn Abi Sa‘īd al-Khudri passed by him, so he asked him: What did you hear your father, Abu Sa‘īd al-Khudri (may Allah be pleased with him) say in relation to what is meant by the mosque that was founded on piety, which Allah Almighty described in His statement: {A mosque that was founded on piety from the first day}? [Surat at-Tawbah: 108] That is to say, it was founded and built on fearing Allah and obeying Him from the very beginning. He told him that Abu Sa‘īd al-Khudri (may Allah be pleased with him) entered upon the Messenger of Allah (may Allah's peace and blessings be upon him) when he was in the house of one of his wives and asked him: "Which of the two mosques is the one founded on piety?" The "two mosques" refer to Qubā’ Mosque and the Madīnah Mosque, which was built by the Prophet (may Allah's peace and blessings be upon him). So, the Prophet (may Allah's peace and blessings be upon him) took a handful of small pebbles from the ground and threw them on the ground, then he answered the question of Abu Sa‘īd al-Khudri (may Allah be pleased with him) saying: "It is this very mosque of yours," i.e., the Madīnah Mosque. This is meant as a form of exaggeration in clarifying that it is the Madīnah Mosque. Thereupon, Abu Salamah ibn ‘Abdur-Rahmān said to ‘Abdur-Rahmān ibn Abi Sa‘īd: "I bear witness that this is how I heard your father," i.e., Abu Sa‘īd al-Khudri (may Allah be pleased with him), "make mention of it," i.e., he had mentioned to me the like of what you mentioned to me about it. The Hadīth clarifies the merit of the Prophet's Mosque and the fact that it was founded on piety..