In mudraj fī al-matn, a narrator blends a statement of his own into the text so that it may appear to be the Messenger’s speech too.
• The addition is in the text, not a narrator’s name.
• In the example, وَهُوَ التَّعَبُّدُ explains the meaning of worship.
• Recognizing it separately preserves the distinction between the report and its explanation.