صحیح ابن حبان
Ibn Hibban
كتاب الطهارة
Book of Purification
باب الغسل - ذكر البيان بأن الغسل يجب على المجامع عند التقاء الختانين وإن لم يكن الإنزال موجودا
Chapter on Ghusl – Clarification that ghusl is required after intercourse when penetration occurs, even without ejaculation
1 hadith
Hadith 1176
Lady Aisha Siddiqa (may Allah be pleased with her) narrates: When the private part meets the private part, then ghusl becomes obligatory. When I and the Prophet Muhammad (peace be upon him) did this, we would perform ghusl.