What is the ruling on money earned from selling ornamental birds while lying about their age or gender, and what must the seller do after repenting?

The Shari'ah forbids deception and lying in buying and selling, and encourages truthfulness in both. Deception in selling obliterates its blessing, but the sale itself is not invalidated by it. From the money earned through a deceptive sale, that which corresponds to the deception—i.e., the increase in price due to it—is unlawful. This excess must be returned to the buyer. If the buyer cannot be identified, then it should be given as charity on their behalf. If the exact amount of unlawful money is unknown, one should estimate to the best of their ability until they are confident that they have given out the rightful amount or more.