that requires it to be deemed ritually impure.

Those who maintain that flowing water is like standing water, and that the threshold of two qullahs (large jarfuls) applies to it—so that impurity renders a portion of the flow impure if it amounts to less than two qullahs—have no proof for this, nor any supporting report from the early generations. This is al-Shāfiʿī’s later position and one of the two positions in Ahmad’s school. Their only grounds are the Prophet’s words—may Allah bless him and grant him peace—

“When water reaches two qullahs, it does not become impure,”

and an analogy between flowing and standing water. Neither provides proof for their position.

As for the hadith, its explicit wording provides no support for them; their argument rests only on its implication. Yet an inference by contrast does not require every unmentioned case to differ from the expressly stated ruling. It requires only that the unmentioned cases not be identical to the stated case. If there is some distinction between them, this establishes that one category was singled out for mention, despite grounds for a general statement, because the ruling applies specifically to it.

Thus, the statement, “When water reaches two qullahs, it does not become impure,” indicates that water below that quantity does not have the same ruling. If, below that quantity, a distinction is made between flowing and standing water, the intended implication is satisfied. This is especially so since the hadith was given in response to their question about standing water in open country, frequented by beasts of prey and other animals.

Accordingly, his statement concerning the well of Budāʿah—

“Water is a means of purification; nothing renders it impure”—

continues to include flowing water. The distinction is that flowing water has the power to remove impurity from other things: when poured over impure ground, it purifies it without itself becoming impure. How, then, could it fail to ward impurity off from itself? Furthermore, flowing water transforms impurity through its flow.