Mukhtasar Sahih Bukhari — Hadith 2128

It is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, that the Noble Prophet, peace and blessings be upon him, said: "(On the Day of Resurrection, in Hell) the distance between the two shoulders (shoulder blades) of a disbeliever will be equal to the distance a fast rider covers in three days."