One purpose of confirmation is to exclude a possible misunderstanding. When a claim might seem exaggerated, figurative, or mistaken, an additional expression can reinforce precisely the intended sense.
«جَاءَنِي زَيْدٌ نَفْسُهُ»
Zayd himself came to me.
This expression is an example of emphasis at word level, not itself two clauses separated by faṣl. It illustrates the principle: just as *nafsuhu* removes doubt about the identity of the person, an entire following clause can exclude a misunderstanding of the preceding assertion. Its role is reinforcement rather than a separate event report.