Sand ablution is known as al

Tayammum is the dry ablution performed with clean sand, dust, or stone when water is not available. You touch the clean surface and wipe your face and hands.

This allows Muslims to purify themselves for prayer when sick, traveling, or when water would cause harm. Allah makes worship easy and does not burden us beyond our ability.

Tayammum shows that cleanliness is important but Allah provides alternatives when needed.