Washing means allowing water to flow over the limb.
His statement, “the face,” refers to that by which one faces another. Its vertical limit extends from the curve of the forehead to the bottom of the beard, and its horizontal limit from ear to ear.
Our saying, “from the curve of the forehead,” has the same meaning as the statement of some scholars, “from the usual hairline of the head” (1), because it reaches the boundary of the forehead, namely its curve. This is what constitutes the part by which one faces another, since the curve itself is recessed and is therefore not part of that which faces another. The evidence is Allah’s saying: “O you who believe, when you rise for prayer, wash your faces” [al-Ma'idah 5:6]. The ruling concerning a beard that extends beyond its normal limit has already been mentioned (2).
The mouth and nose are part of it, and washing the hands, ........
His statement, “The mouth and nose are part of it,” means that they are part of the face. Since they are located in it, they fall within its definition. Accordingly, rinsing the mouth and inhaling water into the nose are among the obligatory elements of ablution, though they are not independent obligations. They resemble the Prophet’s ﷺ statement: “I have been commanded to prostrate upon seven bones: upon the forehead”—and he pointed with his hand to his nose—(3), although the resemblance is not complete in every respect.
His statement, “and washing the hands”: this is the second obligatory element. The author, may Allah have mercy on him, mentioned the hands without qualification, but this must be qualified as extending to the elbows, for when the term “hand” is used without qualification, it refers only to the palm.