Most said that purity is a condition for it, just like the qiblah, and they disagreed about performing tayammum for it for one who fears missing it. Some people said that he should perform tayammum for it, and some people said that he should not perform tayammum for it or pray over it with tayammum. What I say is that purity is not a condition, but I hate turning to God and mentioning Him without legal purity.