Musnad Ahmad 27:1453

Mu'ammal narrated to us, Hammad—meaning Ibn Zayd—narrated to us, Ayyub narrated to us, from Nafi', from Ibn Umar, who said: The Messenger of Allah (ﷺ) said: "{The day when mankind will stand before the Lord of the worlds} [Al-Mutaffifin: 6], {on a day the measure whereof is fifty thousand years} [Al-Ma'arij: 4], in sweat up to the middle of their ears."