It is narrated from Sayyiduna Ibn Mas'ud (may Allah be pleased with him) that he said: "Whoever wishes to divorce in accordance with the Sunnah, as Allah, the Mighty and Majestic, has commanded, let him divorce her in a state of purity, without intercourse."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9577