جَاءَنِي زَيْدٌ نَفْسُهُ — Zayd himself came to me.
جَاءَ: past verb; -nī is the object.
زَيْدٌ: nominative subject, ḍammah.
نَفْسُهُ: nominative semantic emphasis; nafs is mudāf and -hu mudāf ilayh.
-hu: masculine singular pronoun referring to Zayd.
The subject, Zayd, remains distinct from the emphasizer, nafsuhu.