From Sahih Muslim (Hadith 7160):
This hadith has been transmitted on the authority of Abu Bakr b. Abu Musa b. Qais who, on the authority of his father, reported the Apostle (ﷺ) to have said that there would be a tent made of a pearl whose height towards the sky would be sixty miles. In each corner, there would be a family of the believer, out of sight for the others
Reference: Muslim 7160