When One Has an Excuse for Offering Prayer
Issue No.690- If a person has an excuse and is sure that his excuse will cease before the prescribed time ends, it is obligatory that he wait, but if he is certain that his excuse will continue until the end of the prescribed time, it is not obligatory to wait. However, if he considers it probable that his excuse will be ceased, the obligatory precaution is that he should wait, except for tayammum in which case he can offer prayer in the early part of the time.