By Rabbi Berach Steinfeld
Yosef’s brothers did not recognize Yosef when they stood before him because when he was sold into slavery he had not yet grown a beard. The Sforno asks, “Why didn’t the brothers recognize him when they heard his voice? A person’s voice is a definitive characteristic of a person. We see this proven in the Gemara in Gittin, daf chof gimmel, amud alef that teaches us that a blind man may live with his wife since he can discern her by her voice.
There are a few answers to this question. The first answer could be that Yosef was aware that his brothers would recognize him based on his voice so he was very careful not to speak directly to them. There was always an interpreter with him, so the brothers actually did not hear his voice.
There is another answer that can explain the question. One may recognize another person’s voice only if the person is speaking the language they are familiar with them conversing; not if they are speaking in a different language. This could explain why Yosef used the following terminology when he revealed himself to his brothers. He said, “Your eyes are seeing that my mouth is speaking to you.” Rashi explains that Yosef spoke to them in Lashon HaKodesh. The Ramban questions why would that would be a proof of his identity; there could have been other people in Mitzrayim who spoke Lashon HaKodesh! Now that we understand that a person can recognize another person via their voice if they speak a familiar language, Yosef’s words make sense. He was saying now that you see that I am speaking the same language, you can now recognize my voice.
A third answer could be that Yosef spoke with them in a tough way as the posuk says he spoke “kashos-” in a rough manner, not in his regular soft manner. Because of the rough manner of his speech they were not able to recognize his voice.
A final answer is that the same way the brothers were not able to recognize Yosef because he was sold without a beard and subsequently was a bearded person, in addition there was a voice change from the time he was sold to the time he spent in Mitzrayim. His voice went through a maturation process; therefore they could not recognize it.
Please accept my apology for last week’s mistake. The story mentioned took place with the Rashash, not the Maharshal. Thanks to all who emailed and alerted me to the mistake.