A later expression may not restate all the words of the first. It can single out an aspect closely associated with the earlier meaning. Grammatical discussions of apposition of inclusion (بدل الاشتمال) help illustrate this clarifying relation.
«أَعْجَبَنِي زَيْدٌ وَجْهُهُ»
Zayd's face pleased me.
This is an example of apposition within a sentence, not two complete clauses of faṣl. Its limited instructional purpose is to show how a later constituent can specify one aspect of what was mentioned earlier. Clause-level separation must still be analysed in its own context.