Thus it is evident that circularity is inescapable—whether you categorically forbid cursing the doer of the disputed act or allow disagreement on the matter. The conviction you have stated does not disqualify adducing the threatening texts on either assumption, and this is clear.

It may also be said to him: Our purpose in this line of argument is not to prove that the threat itself unquestionably applies to the subject in dispute; rather, it is to establish that the hadith containing the threat may legitimately be cited as evidence for that subject. The hadith conveys two rulings: prohibition and warning. What you have presented seeks only to negate its indication of the warning.

Here, however, we are concerned solely with showing its indication of prohibition. If you maintain that the hadiths threatening the curser do not encompass a curse about which scholars disagree, then no evidence remains to prohibit such a disputed curse. The case before us is precisely of that sort, as mentioned earlier; therefore, if it is not unlawful, it is permissible.

Alternatively, one might say: If no proof has been established for its prohibition, it is not permitted to believe it is prohibited, while the factor that warrants its permissibility is present—namely, the hadiths that curse the one who commits this act. Scholars have differed over the permissibility of cursing him, and on this assumption there is no evidence forbidding it. Consequently, one must act upon the evidence that establishes the permissibility of cursing him, evidence unopposed by any counter-evidence; and this invalidates the objection.

Thus the matter has circled back upon the questioner from another angle, and it has only arisen