From him, from Abd al-Rahman ibn Abi Najran, from Safwan ibn Yahya, from ‘Is ibn al-Qasim, who said: I asked Abu Abdullah عليه السلام about the leftover water (su’r) of a menstruating woman. Imam عليه السلام said: "You may perform Wudu' (ablution) with it. You may also perform Wudu' with the leftover water of a person in a state of Janabah (major ritual impurity) if they are trustworthy (In cleanliness), provided they wash their hands before placing them in the vessel. Indeed, the Messenger of Allah سبحانه وتعالى used to bathe together with Aisha from the same vessel, and they would both bathe together." 4 Leftover water (su’r) – this is the water inside the vessel that remains as ‘leftover’ after having been used by a person, such as by dipping their hands into this vessel to draw water. In this example, the leftover water of a menstruating woman is not inherently impure. However, there is an implicit precaution: if there is a reason to believe the water may have been contaminated (for example, if her hands were impure when she dipped them into the vessel), then caution should be exercised