3 – Anyone who has performed tayammum must make a new tayammum for the next prayer.
4 – The general wording indicates that a fresh tayammum is obligatory for the subsequent prayer, whether the two prayers fall within the same time-frame or each within its own prescribed time.
5 – Supporters of this opinion explain that the purity obtained through tayammum is a concession granted only out of necessity: it merely permits the act of worship and does not, like ablution with water, actually remove the state of ritual impurity.
Disagreement among the scholars:
The jurists differed over whether tayammum lifts the state of impurity as water does, or whether it only allows one to pray and similar acts until water is available, while the impurity itself remains.
Those who held that it removes impurity outright include Abū Ḥanīfah; one narration from Aḥmad; and it was the preference of Shaykh al-Islam and Ibn al-Jawzī.
Mālik, al-Shāfiʿī, and the well-known opinion from Aḥmad maintain that tayammum does not remove impurity but merely permits prayer; hence a person must perform a new tayammum for each prayer time, because the first tayammum lapses when the second time enters.
The position supported by the stronger evidence is the first.
Al-Sharḥ al-Kabīr states: “By analogy, tayammum has the same status as full purification until water is found or a new impurity occurs; this is the view of Saʿīd ibn al-Musayyib, al-Ḥasan, al-Zuhrī, al-Thawrī, and the Ḥanafīs, for it is a purification that enables prayer and therefore is not limited by time, just like purification with water.”
Imam Aḥmad said: “By analogy, tayammum counts as purification until water is found.”
Al-Insāf adds: “This was the choice of the Shaykh, and it is the sounder view.”
As for the ḥadīth under discussion, it is weak; al-Ḥāfiẓ said: “Al-Dāraquṭnī transmitted it with a very weak chain.”
Therefore, the correct ruling is that a person who has performed tayammum may, with a single tayammum, perform as many obligatory and supererogatory prayers as he wishes and may lawfully do whatever one may do in a state of water-based purification, until he finds water or one of the nullifiers of ablution occurs.