Cheng Mo was the concubine in Princess Minghui's mansion, and he was born mute.
His mother was the consort's first wife, and she died in childbirth when giving birth to him. The eldest princess saw that he was pitiful and could not make a sound, so she took him to her room to raise him.
Unexpectedly, thirteen years later, this child married his own brother.
Ps: Shou and gong are not related by blood
Purpose: Feudal superstition is not advisable