Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "Whoever gives an innovated (bid'ah) divorce, we will hold him bound by that innovated divorce."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الخلع والطلاق / 14932