He said, “They lead the prayer for you; if they perform it well, the reward is yours, and if they perform it badly, the reward is still yours while the burden rests on them.”
This subject is exceedingly broad.
He also said, “May Allah curse the Jews; they turned the graves of their prophets into mosques.” He was warning against what they had done. The Companions remarked, “Had it not been for that, his grave would have been made prominent, but he disliked that it be taken as a mosque.” He said this during his final illness.
Five days before his death he said, “Those who came before you used to turn graves into mosques. Beware—do not turn graves into mosques, for I am forbidding you to do that.” 1
When he mentioned the church of Abyssinia, he said, “Whenever a righteous man among them died, they built a mosque over his grave and painted those images inside it. Such people are the worst of creation in the sight of Allah on the Day of Resurrection.” 2
All of these narrations are found in the well-known sound collections.
He also said, “May Allah curse the women who habitually visit graves, and those who build mosques and set up lamps over them.” 3 Reported by al-Tirmidhi and others, who graded it a fair hadith.