How many obligatory prayers can be performed with a single act of Tayammum once the intention is made for one obligatory prayer?
Chapter on Tayammum
Al-Mughni
Book of Purification
Primary text
If a person makes the intention for one obligatory prayer with their Tayammum, they may perform any number of prayers thereafter, including the current obligatory prayer, combining prayers (Jam'), making up missed prayers (Qada'), and performing voluntary prayers before or after the obligatory prayer. This is the position of Abu Thawr. The primary justification is that the purity is valid and permits one obligatory act, therefore it permits others, similar to water purification. Furthermore, after the first obligatory prayer, the remaining Tayammum remains valid and permits further voluntary prayer, thus it permits another obligatory prayer if intended.
Supporting text
Malik and Al-Shafi'i hold that only one obligatory prayer can be performed. A narration from Ahmad suggests only one prayer, necessitating a new Tayammum for the next. This view is supported by a statement attributed to Ibn Abbas that it is from the Sunnah not to pray more than one obligatory prayer with one Tayammum, because it is purification of necessity and should not combine two obligations, just as it cannot cover two prayer times.