I remember when I was with the Messenger of Allah ﷺ and I tied a rock to my stomach because of hunger, and now my zakah is forty thousand. It was narrated from ʿAli ؓ ... and he mentioned the same hadeeth, and said in it. The zakah of my wealth is forty thousand dinars.
لَقَدْ رَأَيْتُنِي مَعَ رَسُولِ اللهِ ﷺ وَإِنِّي لارْبُطُ الْحَجَرَ عَلَى بَطْنِي مِنَ الجُوعِ وَإِنَّ صَدَقَتِي الْيَوْمَ لارْبَعُونَ أَلْفًا