The discussion of istiʾnāf also recognizes that an entire answering element or a substantial understood part may be left unexpressed when the discourse already makes the intended answer clear. Ellipsis works only where context genuinely supports the omitted sense.
«نِعْمَ الرَّجُلُ زَيْدٌ»
How excellent a man Zayd is!
One way to explain the praise construction is through the question “Who is the person being praised?” with Zayd supplying the identification. This is not a claim that there is only one permissible grammatical analysis. The rhetorical point is anticipation and completion.