Musnad Ahmad 27:1373

'Affan narrated to us, Sakhr ibn Juwayriyah narrated to us, from Nafi', from Ibn 'Umar, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said regarding {The Day when mankind will stand before the Lord of the Worlds} [Al-Mutaffifin: 6]: "One of them will sink into his sweat up to the middle of his ears."