• Mudraj: extra material blends into the chain or text and is taken as part of the Hadith. In the cave-of-Ḥirā’ example, ‘وَهُوَ التَّعَبُّدُ’ explained a word.
• Maqlūb: moving something before or after something else changes the chain or text. The charity example exchanged right and left.
Reversal to test a narrator requires disclosure of the original before the gathering ends. Permitted explanation is not unrestricted insertion.