A qalb objection is persuasive only if the same alleged cause truly supports the contrary result without depending on another unproved assumption. For instance, the intention required for an obligatory fast cannot be settled by the word “obligatory” alone; the legal designation of time also matters.
A disciplined test asks:
1. What cause does the proponent put forward?
2. Which ruling is it said to establish?
3. What reversed or opposite result does the opponent derive?
4. Which further proof or material distinction resolves the conflict?
Reversal succeeds through evidence, not clever wordplay.