Abu Dawud

Hadith Commentary: Benefits and Issues: These ahadith establish that if semen (mani) is wet (moist), then it should be washed, and if it is dry, then merely scraping it off is sufficient; washing is not necessary. This is the view of Imam Abu Hanifah rahimahullah, Imam Shafi'i rahimahullah, and Imam Ahmad rahimahullah. However, according to Imam Malik rahimahullah, whether semen is dry or wet, in every case it must be washed.

But regarding the purity or impurity of semen, there is a difference of opinion among the Imams. According to the more authentic narrations from Ali radi Allahu anhu, Sa'd bin Mu'adh radi Allahu anhu, Ibn Umar radi Allahu anhuma, Aisha radi Allahu anha, Imam Shafi'i rahimahullah, and Imam Ahmad rahimahullah, semen is pure. According to Imam Abu Hanifah rahimahullah and Imam Malik rahimahullah, it is impure.
(Sharh Nawawi 1/140)

It is clear that this is merely an academic and intellectual discussion; otherwise, in the case of it being wet, there is no difference of opinion regarding washing it. And, by nature, a person feels aversion if human excretions touch their clothes, whether it is nasal mucus, saliva, blood, or semen.

Hadith Commentary:
Vocabulary of the Hadith:
أُفَرِّكُهُ فَرْكًا:
I would scrape it off.
It is said that the meaning of “فَرَّكَ الشَّيْئَ عَنِ الثَّوْب” is:
to rub or scrape something off from the garment,
and this is only possible
when that thing is stuck in one place.

Benefits and Issues:
From this hadith, it is understood that if semen (mani) gets on the garment, it is not necessary to wash the entire garment; it is sufficient to wash only the area where the semen has touched.
If the semen is not visible and there is only doubt, then merely sprinkling water on the garment is sufficient.

1:
This narration indicates that it is not obligatory to wash semen (mani) from clothing; if it is dry, scraping it off, and if it is wet, cleaning it with something, suffices to purify the garment.
There is a difference of opinion among the scholars regarding whether semen is pure or impure.
Imam Shafi‘i,
Dawud al-Zahiri, and Imam Ahmad are of the view that semen is pure, like nasal mucus and saliva.
Among the Companions, ‘Ali,
Sa‘d ibn Abi Waqqas,
Ibn ‘Umar, and ‘A’ishah radi Allahu anhum also held this position, and in light of the evidences, this view is the stronger one.
Shaykh al-Islam Ibn Taymiyyah and Ibn al-Qayyim also held this view; Shaykh al-Islam’s fatwa is detailed in “al-Fatawa al-Kubra,”
which Ibn al-Qayyim mentioned in “Bada’i‘ al-Nawa’id” as the statement of some jurists, and the hadiths in which washing semen is mentioned are in the context of cleanliness,
not obligation (see Imam al-Tirmidhi’s explanation under the next hadith).

Commentary:
(1)
If impurity (najasah) falls on one part of a garment, it is not necessary to wash the entire garment; it is sufficient to wash only that part from which the impurity is removed.

(2)
If semen (madhah manawiyyah) is wet, the garment should be washed.
If it is dry, scraping it off is sufficient, then the garment should be rubbed and shaken.

(3)
This washing or scraping is for cleanliness and purification.