Sefer HaChinukh
The commandment of the sacrifice of the zavah when she is healed from her discharge: That the zavah offer her sacrifice after she is healed from her discharge - and it is two doves or two young pigeons, as it is stated (Leviticus 16:28-29), "And if she is purified from her discharge, etc. And on the eighth day, she shall take two doves, etc."