Tawus narrates from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that a man came to the Messenger of Allah (peace and blessings be upon him) and said: "O Messenger of Allah (peace and blessings be upon him)! I made zihar from my wife, then on a moonlit night I saw her anklets and she pleased me, so I had intercourse with my wife." He (peace and blessings be upon him) said: "Did Allah not say: 'before they touch one another' [Surah al-Mujadilah: 3]?" He said: "O Messenger of Allah (peace and blessings be upon him)! I have already done it." He (peace and blessings be upon him) said: "Refrain from her until you have offered the expiation."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الظهار / 15264