Al-Lu'lu Wal-Marjan 576 — The Book of Zakât

Abu Dharr Narrated from:

Once I went to the Prophet صلى الله عليه وسلم and he said, "By Allâh in Whose Hands my life is", or probably said, "By Allâh except Whom none has the right to be worshipped), whoever had camels or cows or sheep and did not pay their Zakât, those animals will be brought on the Day of Resurrection far bigger and fatter than before and they will tread him under their hooves, and will butt him with their horns, and (those animals will come in circle) when the last does its turn, the first will start again and this punishment will go on till Allâh عز وجل has finished the judgment amongst the people." ( Sahîh Al-Bukhârî, Hadîth No. 539, Vol. 2 )