Tafsiran Kejadian 45:12: Rashi, Chizkuni, Ramban & Rashbam

והנה עיניכם ראות AND, BEHOLD, YOUR EYES SEE my glory, and that I am your brother, and further כי פי המדבר אליכם THAT IT IS MY MOUTH THAT SPEAKETH TO YOU in the Holy Language) (Genesis Rabbah 93:10).

ועיני אחי בנימין, “and the eyes of my brother Binyamin;” if you do not wish to reveal the fact that I had been sold on account of the oath to that effect that you have sworn, my brother Binyamin was not present at that time, nor has had any knowledge of it, he can reveal the details to my father. Another explanation for the relevance of what Binyamin saw at that time: Binyamin had much more reason to have assumed that I must be dead, seeing that he was not present and had not subsequently become aware of my having been sold, and he therefore needs convincing more than you do. Besides up until now when I only communicated with you through an interpreter, you could have doubted this. Now that you hear me speak in Hebrew, you should no longer doubt that I am who I claim to be.

THAT IT IS MY MOUTH THAT SPEAKETH UNTO YOU. I.e., in the Holy Language. This is the opinion of the commentators,⁴¹Rashi, Ibn Ezra and R’dak. and it is also the translation of Onkelos. It is possible that Joseph said so to them for plausibility and in order to be conciliatory, for the fact that a person in Egypt speaks the Holy Language is not proof that he is Joseph. It is my opinion that the Holy Language was the language of Canaan for Abraham did not bring it there from Ur of the Chaldees or Haran, as they spoke Aramaic there, as is attested to by “the heap.”⁴²Above, 31:47. In Aramaic, Laban named it Yegar-sahaduth (the heap of witness). Thus it is clear that Aramaic was the spoken language in Abraham’s birthplace. Now it was not the language of one man alone; rather, it was the language of the entire land of Canaan, and many people in Egypt knew it, since Canaan was nearby. We would particularly expect knowledge of languages in the case of a ruler for it is usual for kings and rulers to be linguistic. It is just as you see in the case of Nebuchadnezzar who said in the Holy Language, I have dreamed a dream, and my spirit is troubled to know the dream,⁴³Daniel 2:3. because there were the magicians, and the enchanters, and the sorcerers, and Chaldeans,⁴⁴Ibid., Verse 2. people of many languages, as well as from Israel, and they all would understand him. They, however, answered him in Aramaic, as it says, Then spoke the Chaldeans to the king in Aramaic,⁴⁵Ibid., Verse 4. as they were close to him, and sat first in the kingdom,⁴⁶Esther 1:14. and they had the permission to speak to the king. Moreover, just as Joseph came from Canaan to Egypt, many others also came. Besides, the brothers had greater proof that he was Joseph when he mentioned his name and the circumstance of the sale, saying, I am Joseph your brother, whom ye sold into Egypt.⁴⁷Verse 4 here.
The correct interpretation in my opinion is that Joseph is saying: “And, behold, your eyes see, and the eyes of my brother Benjamin, that I, the ruler and lord of all Egypt, am the one telling you with my mouth that I am your brother, and command you to bring down my father to me in order to sustain him. This being so, you will tell my father of all the glory in Egypt, and of all that you have seen⁴⁸Verse 13 here. with your eyes, and you will hurry and bring him down to me for the words I have spoken are true, and I have the power to deliver him and to keep him alive in the famine.”⁴⁹See Psalms 33:19. This is analogous to saying, “for I have spoken my word.” In the Gemara of Tractate Megillah,⁵⁰16b. the Rabbis have said: “As my mouth, so is my heart,” [meaning: “Just as I indicate no hatred against you in my speech, so is my heart free of hatred against you].”