He said: "Then he showed him the greatest sign," meaning: the hand, and it is the greatest of the nine signs with which he came to him.
قَالَ: ﴿فَأرَاهُ الْآيَة الْكُبْرَى﴾ يَعْنِي: الْيَدَ وَهِيَ أَكْبَرُ الْآيَاتِ التسع الَّتِي أَتَاهُ بهَا.