The building of mosques for the worship of Allah is one of the noblest and greatest acts of worship and obedience. Islam urges people to build mosques and respect their sanctity. In this hadith, the Tabi‘i ‘Ubaydullah al-Khawlani narrates that when ‘Uthman ibn ‘Affan wanted to demolish the Prophet’s Mosque and rebuild it with a better design and shape than it was originally, the people disapproved of that and talked a great deal, because of what he was planning to change in the structure of the mosque from how it had been built at the time of the Prophet (blessings and peace of Allah be upon him). That was because the mosque had been built of bricks, with a roof of palm branches, then it had been renovated during the caliphate of ‘Umar (may Allah be pleased with him), but it had the same layout and was built as the Prophet (blessings and peace of Allah be upon him) had built it. But ‘Uthman rebuilt it with engraved stones and plaster, as is explained in a report in Sahih al-Bukhari. Hence the people criticized ‘Uthman a great deal. ‘Uthman (may Allah be pleased with him) was annoyed with them, and he rebuked them and told them that he had heard the Prophet (blessings and peace of Allah be upon him) say: “Whoever builds a mosque, seeking thereby the pleasure of Allah”, meaning that he did it for His sake alone, and not to show off or enhance his reputation, Allah would grant him the best reward that matched the nature of his deed: Allah would build something like it for him in Paradise. The phrase “like it” does not mean that it would be of the same size or of the same quality and design; rather what is meant is that it would be like it in name only. It was also said that what is meant – and Allah knows best – is that Allah would expand his house in Paradise commensurate with his expansion of the mosque in this world, and the structure of that house would be as solid and well-built as he made the mosque, and he would be caused to benefit from what was built for him in Paradise to the extent that the people benefitted from what he built for them in this world. This hadith indicates that sincerity is a condition of attaining reward in all good deeds. It also highlights the virtue of building mosques..