From him, from Al-Abbas, from Ibn Al-Mughira, from Abdullah ibn Bukayr, narrated from Abu Abdullah عليه السلام: I said to Imam عليه السلام: "A man led a group in prayer while he was in a state of janabah (major ritual impurity) and had performed tayammum (dry ablution), whereas they were in a state of purity." Imam عليه السلام said: "There is no problem. When a man performs tayammum, let it be at the end of the time (for prayer). For if he misses water, he will not miss the earth."