The last words spoken by the Prophet ﷺ were, "Know that the worst of people are those who took the graves of their prophets as places of worship."
آخر ما تكلم به النبي ﷺ: واعلموا أن شرار الناس الذين اتخذوا قبور أنبيائهم مساجد.
It was narrated by Imam Ahmad (1691), Bazzar in Kashf Astar (439), and Abu Yaala (872), as well as by Darimi (2501), Humaydi (58), Bukhari in Tarikh al-Kabir (4/57), and Bayhaqi (9/208), all of them through various routes from Ibrahim bin Maymun, who said, Saad bin Samura bin Jundab narrated to us, from his father, from Abu Ubayda, and he mentioned it. Some of them confined the wording to, "Expel the Jews from Hijaz and the people of Najran from the Arabian Peninsula," while others combined this with the matter of taking graves as mosques. Its chain is hasan because of Ibrahim bin Maymun the Hannat, known as Nahhas, the freedman of the family of Samura, for he is hasan al-hadith. Ibn Main deemed him reliable, and Abu Hatim said, "He is truthful." Saad bin Samura was deemed reliable by Nasai, and Ibn Hibban mentioned him in Thiqat (4/294). Haythami mentioned it in Majma (2/28) and attributed it to Bazzar alone, saying, "Its narrators are trustworthy."There is also a report on this subject from Usama bin Zayd, who said, the Messenger of Allah ﷺ said to me, "Bring in my companions to me." So they came in to him, and he uncovered the veil and said, "Allah curses the Jews and the Christians, for they took the graves of their prophets as mosques." This was narrated by Ahmad (21774) and Bazzar (2609), and Tabarani in Kabir (1/127, 131), all of them through various routes from Qays bin Rabi, who said, Jami bin Shaddad narrated to us, from Kulthum Khuzai, from Usama bin Zayd, and he mentioned the same. In it is Qays bin Rabi Asadi, who is daif. He was declared daif by Ibn Main, Ali bin Madini, Ibn Saad, Daraqutni, and others. Abu Dawud said, "He is nothing." Nasai said, "He is not trustworthy." Ajli said, "People declare him daif."As for Ibn Adi, he held a favorable opinion of him, saying, "Most of his narrations are sound." Ibn Hibban said, "When he grew old, his memory deteriorated, and he was afflicted with a bad son, who would insert hadiths into his father's transmissions, and the father, trusting his son, would accept them. So spurious material entered his reports through his son. When the spurious material overwhelmed his sound hadith, and the two could not be distinguished, he deserved to be avoided when it comes to relying on his hadith" Majruhin (2/222), and he did not mention him among the trustworthy narrators. As for Haythami, he said in Majma (2/30), "His narrators are deemed trustworthy," which he said despite the fact that Ibn Hibban did not mention him among the trustworthy narrators.There is also, on this subject, a report from Zayd bin Thabit, that the Messenger of Allah ﷺ said, "Allah curses the Jews, for they took the graves of their prophets as mosques." This was narrated by Ahmad (21605, 21604), Tabarani in Kabir (4907), and Abd bin Humayd (244), all of them through the route of Uqba bin Abdul-Rahman, from Muhammad bin Abdul-Rahman bin Thawban, from Zayd bin Thabit, and he mentioned it. Uqba bin Abdul-Rahman is Ibn Abu Muamar Hijazi, about whom the Hafiz said, "He is unknown." As for Haythami, following his practice of vouching for the reliability of unknown narrators based on what Ibn Hibban mentioned in Thiqat, he said, "His narrators are deemed trustworthy," because Ibn Hibban mentioned him in Thiqat (7/244).