Question: How can we know the abrogating text from the abrogated one if there is no explicit indication of it in a text from the Book, the Sunnah, or consensus, and the date of its revelation is not known? Is it by following the scholars who have authored works on the subject, or by what means?
Answer: If the matter is as described, then what is required with speculative evidences is to refer to contextual indicators (qarā’in). Conflicting evidences are, in most cases, not devoid of such indicators. An example of this is the hadith: “Is there ablution (wuḍū’) due to touching the private part?” For within the question there is some indication that the questioner had heard among the people that ablution is required from touching the private part.
If neither of the two indicators contains anything that points to which is earlier or later, then what appears to me is that the examiner must take the stronger of the two indicators. The aspects of preponderance are many, among them the statement of scholars: this is abrogating, and that is abrogated.
Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.3