There were two grave-diggers in Medina. One would dig a lateral niche (lahd), the other would dig a straight trench (shaqq). The people waited to see which of the two would arrive first. The one who dug the lateral niche came, and so he dug a lahd grave for the Messenger of Allah ﷺ.
كان بالمدينة حفاران، أحدهما يلحد، والآخر يشق فانتظروا أن يجى أحدهما فجاء الذي يلحد، فلحد لرسول الله ﷺ.
Ibn Saad narrated it (2/295) from Yazid bin Harun and Hisham Abu Walid Tayalisi. Yazid said, "He said, he informed us," while Hisham said, "He informed us," Hammad bin Salama, from Hisham bin Urwa, from his father, from Ayesha, and so he related it, and its chain of transmission is sahih. Malik narrated it in Muwatta from Hisham bin Urwa, from his father, as a mursal report.As for what Ibn Majah narrated (1558) through another route from Ayesha, who said, when the Messenger of Allah ﷺ died, they disagreed about whether to make a niche grave or a trench grave, until they argued about it and their voices were raised. Umar said, "Do not raise your voices near the Messenger of Allah ﷺ, whether alive or dead," or words to that effect. So they sent for both the man who used to dig trench graves and the man who used to dig niche graves. The one who dug niche graves came, and he made a niche grave for the Messenger of Allah ﷺ, and then he ﷺ was buried.Its chain of transmission includes Ubayd bin Tufayl al-Muqri, about whom Hafiz said, "Unknown." And his teacher Abdul-Rahman bin Abu Mulaykah al-Qurashi, who is Abdul-Rahman bin Abu Bakr bin Ubaydullah bin Abu Mulaykah, about whom Hafiz said, "Daif," and he also weakened him in Talkhis (2/128). As for Busiri, he did not notice this and said, "Its chain of transmission is sahih, its narrators are trustworthy."