The source explicitly extends the present chapter’s scope:
«والمراد بالسنة ههنا ما هو شامل لأقوال الصحابة وأفعالهم أيضاً»
In this discussion, Sunnah is intended broadly enough to include the sayings and actions of the Companions as well.
This does not mean every Companion’s own statement becomes a direct Prophetic hadith. The author includes Companion reports in the scope of discussion for their proper jurisprudential assessment.
The attribution remains distinct: a Prophetic saying belongs to the Prophet ﷺ, while a Companion’s independent statement is an athar or Companion opinion. Their respective evidentiary force must be determined separately.