He ﷺ replied, “When madhi is emitted he must wash his penis until the heat-generated discharge withdraws, by sprinkling it with water. After that he should perform wudu, for it has come out from one of the two exits, and whatever leaves either of them nullifies wudu.” In this answer the Prophet ﷺ gave the questioner both a legal ruling and a medical guideline.

Scholarly disagreement
The Hanbalis and some of the Malikis hold that the entire penis must be washed, citing this ḥadith and others in which washing the penis is mentioned explicitly; in ordinary language the term applies to the whole organ. The majority, however, require washing only the area actually touched by the madhi, because that alone is the reason for cleansing and the ruling should not extend beyond it.

The first view is stronger for several reasons:

1. Washing the whole organ is the literal sense of the ḥadith; restricting it to a part is figurative and would need compelling evidence.
2. Madhi resembles semen in the cause of its emission, the closeness of their color, and other aspects, so it is comparable to a minor form of janabah in which a full bath is waived but washing the private parts remains.
3. Since it seeps out due to the heat of desire, sprinkling the entire penis is appropriate; the cooling helps the discharge to contract.

Points derived from the ḥadith

1. Madhi is impure and must be washed, though a small amount may be excused because of hardship, as some scholars state.
2. Its emission breaks wudu, for it issues from one of the two exits.
3. Washing the penis is obligatory. In some reports the words “and the testicles” are also mentioned.
4. It does not require a full ritual bath like janabah; there is consensus on this.
5. Stones or similar means are not enough to remove madhi, unlike urine; water is indispensable.

Doubt about having broken wudu
ʿAbbad ibn Tamim related from his uncle ʿAbd Allah ibn Zayd ibn ʿAsim al-Mazini that a man who imagined he felt something during the prayer was mentioned (1) to the Prophet ﷺ, and he said, “He should not leave the prayer unless he hears a sound or detects an odor.”