وقد يشترط فيه الكتاب بخلاف النبي فإنه أعم
Some stipulate a scripture for a messenger, while regarding the term prophet as broader.
Several distinctions are reported. Some treat messenger and prophet as equivalent; some associate messengership with a new law or a specific mission; others distinguish modes of reception or the community addressed. These are competing technical accounts, not a single unanimous definition.
The common theological core remains divine communication. A disputed boundary between the words rasūl and nabī must not be silently transformed into an undisputed doctrine.