Sayyiduna Abu Hurayrah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) said: "Every son of Adam has his share of zina. The eyes commit zina, and their zina is looking; the hands commit zina, and their zina is seizing; the feet commit zina, and their zina is walking; the mouth commits zina, and its zina is kissing; and the heart intends or wishes, and the private part confirms that or denies it." Abu Hurayrah bore witness to this, that he heard it and saw it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13511