Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrated that Sayyiduna Umar (may Allah be pleased with him) came to the Messenger of Allah (peace and blessings be upon him) and said: O Messenger of Allah, I am ruined. He (peace and blessings be upon him) said: "What has ruined you?" He said: I turned my saddle around (that is, I approached my wife in a different manner). He (peace and blessings be upon him) gave him no answer until this verse was revealed: "Your wives are a tilth for you, so come to your tilth however you wish", meaning: from the front or from behind, but avoid the blood, and avoid relations during menstruation.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12265