Musannaf Ibn Abi Shayba 37:111

Jarir narrated to us, from Abd al-Aziz ibn Rufay’, from Ubayd Allah ibn al-Qibtiyya, who said: Al-Harith ibn Abi Rabi’ah and Abd Allah ibn Safwan entered upon Umm Salamah, and I was with her. They asked her about the army that would be swallowed by the earth, and that was during the time of Ibn al-Zubayr. She said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "A seeker of refuge will seek refuge in the House (the Kaaba), and an army will be sent to him. When they are in a desert (bayda') of the land, they will be swallowed by the earth." We said: "O Messenger of Allah, what about the one who was unwilling?" He said: "He will be swallowed by the earth along with them, but he will be resurrected on the Day of Resurrection according to his intention." Abu Ja’far said: It is the desert (bayda') of Medina.