«وحكم بيان التغيير: أنه يصح موصولاً ولا يصح مفصولاً»
Modification is valid when connected to the original statement and invalid when detached from it.
If an admission of “I owe ten dirhams” is completed and the speaker later adds “except three,” that later utterance does not automatically reduce the already complete admission. In one connected sentence, “ten except three” is an admission of seven from the outset.
A condition likewise needs to be connected to the declaration it qualifies. Taqrir and tafsir can be separate because they do not retract or curtail a completed ruling.
Decisive question: Does the later language reveal what the earlier words meant, or does it attempt a new reduction or alteration of a completed legal statement?