Sayyiduna Abu Ayyub Ansari (may Allah be pleased with him) narrates: Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) informed me of this. He says: I asked, "O Messenger of Allah! A man goes to his wife (i.e., has intercourse with her) and he does not ejaculate." The Prophet (peace and blessings be upon him) said: "The woman should wash the moisture that has touched her and perform ablution, then offer prayer."
Hadith Referenceصحیح ابن حبان / كتاب الطهارة / 1169
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح: ق.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح، على شرطهما.