Sahih Ibn Khuzaymah

And the explanation of the evidence that Allah Almighty makes a certain obligation mandatory in the Holy Qur’an in one sense, and then makes the same obligation mandatory in another sense through the tongue of His Prophet (peace be upon him). According to the command of Allah Almighty in the Holy Qur’an, defecation and sexual intercourse with women make ablution obligatory, because Allah Almighty has commanded the sick and the traveler to perform tayammum after defecation and sexual intercourse with women in the absence of water. Therefore, according to the command of the Book of Allah, a healthy person, in the presence of water, must perform ablution after defecation and sexual intercourse with women, because tayammum with pure earth has been made a substitute for ablution for the traveler and the sick in the absence of water. And the Noble Prophet (peace be upon him) informed that ablution becomes obligatory due to things other than defecation and sexual intercourse with women. In the narration of Sayyiduna Safwan bin Assal (may Allah be pleased with him), the Noble Prophet (peace be upon him) stated that each of urination and sleep makes ablution obligatory, even though the one who urinates and the one who sleeps are other than the one who defecates and the one who has sexual intercourse with women. Soon, with the will and help of Allah Almighty, I will mention such events that make ablution obligatory, which are established by the command of the Prophet (peace be upon him), and those are other than the events mentioned in the Holy Qur’an, i.e., other than defecation and sexual intercourse with women. Contrary to the statement of that person, who is not a reliable scholar, who says that it is not permissible for Allah Almighty to mention a command in the Holy Qur’an and make it conditionally obligatory, and then the same command becomes obligatory without the condition mentioned in the Holy Qur’an.