سُلِبَ زَيْدٌ ثَوْبُهُ — Zayd had his garment taken away.
سُلِبَ: past passive verb.
زَيْدٌ: nominative passive subject (nāʾib fāʿil), antecedent.
ثَوْبُهُ: nominative badal al-ishtimāl in the book’s analysis; thawb is mudāf and -hu is mudāf ilayh.
-hu: pronoun referring to Zayd.
This is the source’s intended analysis: thawbuhu is badal of association, not a bodily component.