What should a man do who said to his wife, "You are to me like my mother," and then had intercourse with her, and what is the ruling on this act?

What occurred from you is considered zhihar, and you must repent and seek forgiveness and refrain from conjugal relations with your wife until you expiate the zhihar as mentioned in Surat Al-Mujadilah: freeing a slave, and if you cannot find one, then fasting for two consecutive months before you touch each other, and if you are unable to do that, then feeding sixty poor people. If zhihar is repeated before expiation, only one expiation is required.