It is narrated from Sayyiduna Thawban (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "I will surely find people of my Ummah who will come on the Day of Resurrection with good deeds like the mountains of Tihamah, and Allah, the Mighty and Majestic, will make those deeds scattered dust." The Companions said: "O Messenger of Allah, describe them to us so that we do not become among them without knowing it." He (peace and blessings be upon him) said: "Indeed, they are your own brothers, but they are people who, when they are alone with what Allah has made sacred, violate it."
This is how (the narrator's name) appears in the printed Dar al-Haramayn edition, whereas the correct form is "Ubaydullah Abu Muhammad Ibn al-Sannam al-Ramli".
Hadith Referenceالمعجم الأوسط / باب العين / 4632
Hadith Takhrij«أخرجه ابن ماجه فى «سننه» برقم: 4245، والطبراني فى «الصغير» برقم: 662»