"Indeed, he is your chief" in sorcery; meaning: your most learned. "Then I will surely cut off your hands and your feet on opposite sides" (meaning): the right hand and the left foot. "And you shall surely know which of us" (meaning): I or Moses "is more severe in punishment and more enduring."
﴿إِنَّه لكبيركم﴾ فِي السِّحْرِ؛ أَيْ: عَالِمُكُمْ ﴿فَلأُقَطِّعَنَّ أَيْدِيكُم وأرجلكم من خلاف﴾ الْيَدِ الْيُمْنَى وَالرِّجْلِ الْيُسْرَى ﴿وَلَتَعْلَمُنَّ أَيّنَا﴾ يَعْنِي: أَنَا أَوْ مُوسَى ﴿أَشَدُّ عَذَابًا وَأَبْقَى﴾.