(17) CHAPTER. If someone while in the mosque remembers that he is Junub , he should leave (the mosque to take a bath) and should not perform Tayammum.
Narrated Abu Huraira: Once the call (Iqama) for the prayer was announced and the rows were straightened. Allah's Apostle came out; and when he stood up at his Musalla, he remembered that he was Junub. Then he ordered us to stay at our places and went to take a bath and then returned with water dropping from his head. He said, Allahu-Akbar , and we all offered the prayer with him.