The Shaykh (Al-Mufid), may Allah سبحانه وتعالى support him, said: "If a person suspects that impurity has touched his garment but is not certain, he should sprinkle it with water. However, if he is certain that impurity has occurred and knows its exact location, he must wash it with water. If the exact spot is unknown, then he must wash the entire garment with water to ensure its purity and eliminate any doubt or uncertainty." The foundation of this matter is that if impurity occurs on a garment, it is forbidden to pray in it. If the location of the impurity is unknown, washing the entire garment guarantees its purification, removing any uncertainty regarding its cleanliness. And this also indicates it.
