(Devarim 22:7) "Send, shall you send away the mother-bird": This is a positive commandment. If he sent her away and she returned — even four or five times — he is obligated to continue sending her, it being written "Send shall you send." But if he sent her and she returned to his hand, he is exempt from sending her again. "Send shall you send the mother-bird": Scripture speaks of (sending away) females and not males.