with his tayammum for an obligatory prayer, he may pray with it as many prayers as he wishes, so he may pray the current [obligatory] prayer, combine two prayers, perform missed prayers (fawa'it), and perform supererogatory prayers before and after the prayer. This is the opinion of Abu Thawr. Malik and Al-Shafi'i said: He may not pray two obligatory prayers with it. It has been narrated from Ahmad that he said: He shall not pray with tayammum except for one prayer, then he performs tayammum for the other. This could possibly mean the same as their opinion, based on what was narrated from Ibn Abbas, who said: "It is from the Sunnah that one does not pray with tayammum except one prayer, then he performs tayammum for another." This is the requirement of the Sunnah of the Prophet (peace be upon him), and because it is a purity of necessity, he should not combine two obligatory prayers with it, as if they were in two different times. Our evidence is that it is a valid ritual purity that has rendered one obligatory prayer permissible, so it renders two obligatory prayers permissible, like water-based purity. Also, after the first obligatory prayer, it remains a valid tayammum that permits supererogatory prayer; he intended the obligatory prayer by it, so he may pray an obligatory prayer with it, like in the state of its initiation. Furthermore, purity in the fundamental principles (usul) is restricted by time rather than the act, such as the purity of one wiping over the leather socks (khuffayn)—which applies to supererogatory prayers—and the purity of a woman in istihada. Additionally, every tayammum that permitted a prayer permits that which is of its same category, as evidenced by supererogatory prayers. As for the hadith of Ibn Abbas, it is narrated by Al-Hasan ibn Umarah, who is weak. Moreover, it is possible that he intended [that he should not pray] two prayers in two different times with it, evidenced by the fact that it is permissible to pray multiple supererogatory prayers with it and to combine two prayers—one obligatory and one supererogatory. The prohibition of combining two obligatory prayers of different times only occurred due to the invalidation of the tayammum by the departure of the time of the first one among them.

Once this is established, Al-Khiraqi only mentioned the performing of missed prayers and supererogatory prayers, and he did not mention combining two [obligatory] prayers, and likewise Imam Ahmad mentioned it. Thus, it is possible that it is not permissible to combine two prayers.