Musnad Ahmad 27:1615

Sulayman ibn Hayyan narrated to us, Ibn 'Awn narrated to us, from Nafi', from Ibn 'Umar, from the Prophet (peace and blessings of Allah be upon him), who said: "{The day when mankind will stand before the Lord of the worlds} [Al-Mutaffifin: 6]." He said: "One of them will stand in his sweat up to the middle of his ears."