Taharah is the basic state of things

A: All praise be to Allah Alone, and peace and blessings be upon His Messenger, and his family and Companions. Taharah (purity) is the basic state of things. No object or place is to be judged Najis (impure) unless we find evidence that it is, (Part No. 5; Page No. 366) and we are certain that one of the dictated kinds of Najasah (impurity) is present in that exact place. Without these two conditions, a Muslim can pray anywhere and his Salah (prayer) is valid.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.