It was narrated that 'Aishah said:"I often scraped it (semen) from the garment of the Messenger of Allah with my hand
Hadith No. 537
Sunan Ibn Majah
Gradings:
Al-Albani:
Sahih
Muhammad Fouad Abd al-Baqi:
Sahih
Shuaib Al Arnaut:
Sahih
Zubair Ali Zai:
Sahih Muslim