for prayer, so practicing Ijtihad is permissible for its sake, just as if the Qibla were indistinguishable. Also, ritual purity is sometimes performed based on certainty and other times based on conjecture (Zann). This is why it is permissible to perform Wudu with a small amount of water that has changed, where the cause of its change is unknown.

Ibn al-Majishun said: One should perform Wudu with each one of them and pray with it. [And by this] (6) Muhammad ibn Maslama said, except that he said: He must wash off what touched him from the first; because it was possible for him to perform his obligatory duty with certainty, so it became binding upon him, just as if a pure item were indistinguishable from a purifying one, or as if he forgot one prayer from a day and does not know which one it is, or if garments were indistinguishable to him.

Our position is that a permissible item has become indistinguishable from a prohibited one in a matter where necessity does not permit it, so practicing Ijtihad is not allowed, just as if the number were equal according to Abu Hanifah, and as if one of them were urine according to al-Shafi'i, for he has conceded this, and his companions apologized for it by stating that it has no basis in ritual purity.

We say: This water has lost its original status of purity and has become impure, so there is no trace left of the original status that has vanished. Furthermore, urine was once water, so it has a basis in ritual purity, like this impure water.

Their statement that "if the number of pure items increases, the side of permissibility becomes stronger" is invalidated by the case where one's sister is indistinguishable among one hundred women, or a dead animal is indistinguishable from ritually slaughtered animals; in these cases, practicing Ijtihad is not permitted, even if the permissible items are numerous. As for when she is indistinguishable among the women of Egypt, it is difficult to avoid all of them, and for that reason, marriage is permitted for him without Ijtihad. Regarding the Qibla, it is permitted to abandon it due to necessity, such as in a state of fear, and it is also permitted during travel for supererogatory (Nafl) prayer, and because one's Qibla is whatever one directs oneself toward based on conjecture. Even if it becomes clear to him with certainty that he was mistaken, he is not required to repeat it, unlike our issue. As for water that has changed without a known cause, it is permissible to perform Wudu with it based on the original status of purity, even if he assumes it is impure, and it does not require Ijtihad. In our issue, the certainty of purity is countered by the certainty of impurity, so it retains no ruling; that is why it is not permissible to use it without Ijtihad. Furthermore, their analogy is invalidated by the case where one of them is urine and the other is water.

The validity of what we have said is demonstrated by the fact that if he performed Wudu from one of the two vessels and prayed, then it became his strongest assumption during the second prayer that the other one was the pure one, so he performed Wudu with it and prayed without washing off the traces of the