As for the fact that I mean tayammum instead of the minor purity, it is that it qualifies him as having occurred in a specific issue and not in faith, due to the lack of a text from the Qur’an or the Sunnah or consensus on that. Just as it is permissible for him to perform tayammum in this minor purity in exchange for it, it is permissible for him to make analogy in ruling on that issue. Perhaps there is a common cause between this issue, for which there is no pronounced ruling, and another issue for which there is a pronounced ruling, whether in the Qur’an, Sunnah, or consensus .