Shaykh Abdul-Rahim Reasat is asked about performing tayammum and prayer in spaces that are visibly unclean or known to be.
Assalam alaykum wa rahmat Allah wa barakatuh.
If salah is prayed on dry earth or grass on which animals have urinated or excreted will it be valid according to the four Imams?
Wa alaykum assalam wa rahmat Allah wa barakatuh.
I pray you are well.
In the Hanafi school it is valid to pray on any piece of land which once had impurity on it, as long as it has (a) dried, and (b) no trace of the impurity remains. Traces of impurity would be smell, taste, and color.
Tayammum, however would not be permissible, because the condition for the validity of tayammum is pure and purifying earth. The contact of the impurity with the ground negates this. (Shurunbulali, Maraqi al-Falah)
If water flows on the ground, or it rains, then all four schools deem it permissible to pray on as long as there is no visible impurity, such as animal droppings, etc. (Al-Mawsuʿa al-Kuwaitiyya)
May Allah bless you with the best of both worlds.
Checked and approved by Shaykh Faraz Rabbani.