Explanation

Tayammum is the Islamic act of dry Ritual purification using purified sand or dust

The verse of Tayammum (dry ablution) was revealed during Battle of Banu Al-Mustaliq

in Al-Ma'idah contains the order of wuzu, Ghusal, and Tayammum

Tayammum is valid only for one obligatory Salah

Tayammum is obligatory on 4 (AH)

while 

Wazu is obligatory on 5(AH)

ND23-6-2023