ויבך יוסף בדברם אליו, “Joseph wept when they were speaking to him.” As soon as the brothers merely mentioned the name of their father Joseph already started weeping. This was due to the great love he had for his now departed father. This stirred his sense of compassion, especially seeing that his brothers asked his forgiveness. The Torah does not spell out that Joseph actually forgave his brothers. Our sages (Bava Kama 92) point out that if a person has wronged his fellow man and regrets this wrong and determines not to act in the manner which had offended his fellow man he is not forgiven by G’d until after he has made an effort to obtain forgiveness by the aggrieved party first. At any rate, the Torah is not on record anywhere that Joseph did forgive his brothers. This was the reason why the sin committed against Joseph resulted in the ten martyrs being executed by torture at the hands of the Romans.
(יח) וַיֵּלְכוּ֙ גַּם־אֶחָ֔יו וַֽיִּפְּל֖וּ לְפָנָ֑יו וַיֹּ֣אמְר֔וּ הִנֶּ֥נּֽוּ לְךָ֖ לַעֲבָדִֽים׃ (יט) וַיֹּ֧אמֶר אֲלֵהֶ֛ם יוֹסֵ֖ף אַל־תִּירָ֑אוּ כִּ֛י הֲתַ֥חַת אֱלֹהִ֖ים אָֽנִי׃ (כ) וְאַתֶּ֕ם חֲשַׁבְתֶּ֥ם עָלַ֖י רָעָ֑ה אֱלֹהִים֙ חֲשָׁבָ֣הּ לְטֹבָ֔ה לְמַ֗עַן עֲשֹׂ֛ה כַּיּ֥וֹם הַזֶּ֖ה לְהַחֲיֹ֥ת עַם־רָֽב׃ (כא) וְעַתָּה֙ אַל־תִּירָ֔אוּ אָנֹכִ֛י אֲכַלְכֵּ֥ל אֶתְכֶ֖ם וְאֶֽת־טַפְּכֶ֑ם וַיְנַחֵ֣ם אוֹתָ֔ם וַיְדַבֵּ֖ר עַל־לִבָּֽם׃
(18) His brothers went to him themselves, flung themselves before him, and said, “We are prepared to be your slaves.” (19) But Joseph said to them, “Have no fear! Am I a substitute for God? (20) Besides, although you intended me harm, God intended it for good, so as to bring about the present result—the survival of many people. (21) And so, fear not. I will sustain you and your children.” Thus he reassured them, speaking kindly to them. [literally, "and speaking to their hearts"]
כתיב (ויקרא יט) "לא תשנא", וביוסף אומר (בראשית נ) "וינחם אותם וידבר על לבם". כתיב (ויקרא יט) "לא תקום ולא תטור", וכתיב (בראשית נ) "ואתם חשבתם עלי רעה אלהים חשבה לטובה". (ויקרא כה) "וחי אחיך עמך", (בראשית מז) "ויכלכל יוסף את אביו".
It is written (Leviticus 19:17) "Do not hate your brother in your heart." And of Joseph it is written (Genesis 50:21) "And he counseled them and he spoke to their hearts." It is written (Leviticus 19:18) "You shall not take revenge and you shall not bear a grudge," and (in respect to Joseph, Genesis 50:20) "And you contemplated evil against me, but G d contemplated it for the good." (Leviticus 25:36) "And let your brother live with you." (Genesis 47:12) "And Joseph sustained his father and his brothers, etc."
And from all of this awesome episode we can understand how much one must guard his tongue and his deeds. And also, from [the account of] Joseph, we can understand his holy trait, viz. (Ibid. 45:5): "And now, do not be grieved, and do not vex yourselves that you sold me here." And, similarly, at the end of the parshah (Ibid. 50:21): "And he comforted them and he spoke to their hearts." And witness further the greatness of Joseph, who did not tell his father what had been done to him, until it was revealed to him prophetically before his death, as it is written [(Jacob speaking)] (Ibid. 49:23): "They [the brothers] embittered him and they antagonized him and they hated him, etc." And, more than this, we find in the words of Chazal that Joseph took care not to be alone with his father, so that his brothers not suspect him of telling his father what he had suffered at their hands.
וידבר אל לבם means HE SPOKE words that found ready entrance INTO THEIR HEART: Before you came down hither people spread rumours about me that I was born a slave; through you it became public that I am a free-man by birth. If I were to kill you what would people say? “He saw a party of fine young men and he prided himself on his relationship with them, saying “These are my brothers”, but afterwards he killed them. Have you ever heard of a man killing his brothers?!” (Genesis Rabbah 100:9) Another interpretation is: He said to them, “Ten lights could not extinguish one light; how, then, can one light extinguish ten lights?” (Megillah 16b).
עשרה נרות לא יכלו לכבות נר אחד וכו'. כי י"ב שבטים כנגד י"ב כוכבים המאירים את כל העולם ולכ"א להם עשרה נרות ר"ל אף שהיו חושבים להרוג אותו הי' ניצול מידם וכ"ז מפני שהיה כל אחד מן השבטים דומה למזל ברקיע אשר א"א ליאבד כ"ש שהוא יחיד לא יכול לאבדם כו'. אבל א"ל דאין יכול להרוג עשרה דזה אין ראיה דיוסף היה מלך והיה יכול לצוות על אלף אנשים להרוג אותם. [גור אריה]:
Ten lights cannot extinguish one light... [You might ask: Why did Yoseif compare them to lights? The answer is:] Because the twelve tribes correspond to the twelve stars which illuminate the whole world. Therefore he mentioned to them “ten lights.” I.e., he was saying that despite their plan to kill him, he was saved from them because each tribe is like a constellation in the heavens which cannot be destroyed. And surely he alone is unable to destroy them. But it cannot simply mean that [since ten could not kill him, surely] he cannot kill ten. This would be no proof because Yoseif was a king and could order a thousand people to kill them. (Gur Aryeh)
This is also what is written in connection to Yosef: “that my own mouth is speaking to you” (Genesis 45:12). Rashi explains: “As my mouth is, so is my heart.” In other words, he shone his nekudah into his vav; he shone “My mouth utters wisdom” into “and the meditations of my heart are understanding.” And it is written of him (Genesis 50:21), “and he spoke to their hearts,” which Rashi explains: words that calm the heart. That is, he shone his encompassing nekudah into all <their> hearts.
Thus it is that as a result of these three nekudot [the heart is inspired]. That is, [through] the binding to the tzaddikim and their shining into him, because they are the encompassing nekudah, they inspire his heart; and through speaking with his friend, each person is also able to shine into and inspire his friend’s heart; and through himself, by engaging in private conversation with His Maker <in hitbodedut>, he can also inspire his own heart by means of “My mouth utters wisdom” and so remove the foreskin of the heart, <the evil loves,> from himself.
(16) Cut away, therefore, the thickening about your hearts and stiffen your necks no more. (17) For the LORD your God is God supreme and Lord supreme, the great, the mighty, and the awesome God, who shows no favor and takes no bribe, (18) but upholds the cause of the fatherless and the widow, and befriends the stranger, providing him with food and clothing.— (19) You too must befriend [lit. "love"] the stranger, for you were strangers in the land of Egypt.