وَالسَّارِقُ وَالسَّارِقَةُ فَاقْطَعُوا أَيْدِيَهُمَا
“As for the male thief and the female thief, cut off their hands.” (Al-Ma'idah 5:38, relevant passage)
The textbook treats the ordinary sense of al-sariq as apparent while raising a question about its application to two particular examples: the tarrar and the nabbash. This is its demonstration of khafi.
The verse concerns a prescribed legal penalty, whose application is subject to legal conditions and competent adjudication. Our concern here is not implementing a penalty but the usuli classification of a special case.