It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: If a man approaches his wife, then wishes to approach her again, he should perform ablution.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 11227
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد حسن، م: 308