وَقَالَ أَبُو يُوسُفَ وَمُحَمَّدٌ: إِذَا صَارَ ظِلُّ كُلِّ شَيْءٍ مِثْلَهُ
Translation: Abu Yusuf and Muhammad said: when each object’s shadow becomes equal to its length.
For the two disciples, Dhuhr ends at one mithl; in the stated view of Abu Hanifah, it ends at two mithls. Both measures exclude fay’ al-zawal.