Another interpretation, “you shall surely send away [shale’aḥ teshalaḥ]” – the Rabbis say: Why is this [verb written] twice? It is so that if this mitzva presents itself to you a second time, do not say: ‘I have already fulfilled my obligation.’ Instead, each time it presents itself to you, you must fulfill it. Another interpretation, “you shall surely send away [shale’aḥ teshalaḥ]” – the Rabbis say: If you sent away [the mother in accordance with] the mitzva of the nest, you will be privileged to send away a Hebrew slave.11That is, you will be wealthy enough to purchase a Hebrew servant, who is freed at the end of seven years’ service.
From where is this derived? It is as it is stated: “But when you send him free away from you” (Deuteronomy 15:13). Another interpretation, “you shall surely send away [shale’aḥ teshalaḥ] the mother” – if you fulfil this mitzva, you will hasten the coming of the messianic king, in whose regard sending is written, as it is stated: “Who send out the foot of the bull and the donkey” (Isaiah 32:20).12The bull is an allusion to the proto-messianic king, a descendant of Joseph, in whose regard it is written: “A firstborn bull is his majesty” (Deuteronomy 33:17), and the donkey alludes to the messianic king, a descendant of David, in whose regard it is written: “Your king will come to you…he is humble, and riding on a donkey” (Zechariah 9:9).
Another interpretation [shale’aḥ teshalaḥ], Rabbi Tanḥuma said: If you fulfil this mitzva, you will hasten the coming of Elijah the prophet of blessed memory, in whose regard sending is written: “Behold, I am sending Elijah the prophet to you” (Malachi 3:23), and he will come and comfort you. From where is this derived? It is as it is written [of Elijah]: “He will restore the heart of parents with children” (Malachi 3:24).