Kli Yakar connects the weeping to Yosef’s distress over the brothers’ past sin and to the emotional force needed to transform estrangement into repentance and reconciliation.
הַעוֹד אָבִי חָי וְגוֹ׳. אַף עַל פִּי שֶׁכְּבָר אָמְרוּ לוֹ שֶׁהוּא חַי, כַּמּוּבָן מִכָּל דִּבְרֵי יְהוּדָה, מִכָּל מָקוֹם חָשַׁב יוֹסֵף: אוּלַי אָמְרוּ כֵן כְּדֵי שֶׁיִּכָּמְרוּ רַחֲמָיו עַל הַזָּקֵן וְלֹא יִגְרֹם לוֹ מִיתָה, כִּי נַפְשׁוֹ קְשׁוּרָה בְּנַפְשׁוֹ. עַל כֵּן שְׁאָלָם שֵׁנִית ״הַעוֹד אָבִי חָי?״, וְלִבָּם לֹא כֵן יְדַמֶּה, וְחָשְׁבוּ שֶׁלֹּא נִתְכַּוֵּן לִשְׁאוֹל אִם הוּא חַי אוֹ לֹא, אֶלָּא שֶׁבָּא לְהַזְכִּיר עֲוֹנָם. עַל כֵּן אָמַר ״הַעוֹד אָבִי חָי״, לֹומַר שֶׁאָבִיו הוּא וְלֹא אֲבִיכֶם, כִּי לֹא חַסְתֶּם עַל צַעֲרוֹ כְּאִלּוּ אֵינוֹ אֲבִיכֶם. עַל כֵּן נִבְהֲלוּ וְלֹא יָכְלוּ לַעֲנוֹת דָּבָר. וְעוֹד טַעַם אַחֵר עַל בֶּהָלָה זוֹ, לְפִי שֶׁאָמַר ״אֲנִי יוֹסֵף״ וְלֹא הִזְכִּיר ״אֲחִיכֶם״, עַל כֵּן נִבְהֲלוּ נֶחְפְּזוּ שָׁם רְעָדָה אֲחָזָתַם, כִּי אָמְרוּ פֶּן יְבַקֵּשׁ לִהְיוֹת אוֹיֵב וּמִתְנַקֵּם וְהִסִּיעַ אֶת עַצְמוֹ מִן הָאַחְוָה, כַּאֲשֶׁר עָשׂוּ הֵמָּה לוֹ שֶׁהִסִּיעוּ אֶת עַצְמָם מִן הָאַחְוָה, כְּמוֹ שֶׁפֵּרֵשׁ רַשִׁ״י עַל פָּסוּק ״נָסְעוּ מִזֶּה״ (בראשית לז:יז). עַל כֵּן אָמַר לָהֶם שֵׁנִית ״אֲנִי יוֹסֵף אֲחִיכֶם אֲשֶׁר מְכַרְתֶּם אֹתִי מִצְרָיְמָה״, אַף עַל פִּי שֶׁלְפָחוֹת הָיָה לָכֶם לִמְכֹּר אוֹתִי לְאֵיזוֹ אֻמָּה אַחֶרֶת שֶׁאֵינָן שְׁטוּפֵי זִמָּה כָּל כָּךְ, מִכָּל מָקוֹם אֲחִיכֶם אָנִי, וְאַל יִחַר בְּעֵינֵיכֶם אֲשֶׁר מְכַרְתֶּם אֹתִי הֵנָּה לְמִצְרַיִם, כִּי לְמִחְיָה שְׁלָחַנִי אֱלֹהִים, כִּי רוֹאֶה אֲנִי שֶׁנִּתְגַּלְגֵּל הַדָּבָר שֶׁבָּאתִי בֵּין שְׁטוּפֵי זִמָּה וְקָרָה לִי מִקְרֶה בְּאֵשֶׁת פּוֹטִיפַר שֶׁכָּבַשְׁתִּי אֶת יִצְרִי, וְעַל יְדֵי זֶה זָכִיתִי לִהְיוֹת רוֹעֶה יִשְׂרָאֵל זָן וּמְפַרְנֵס, כְּמוֹ שֶׁכָּתוּב (בראשית מט:כד) ״וַתֵּשֶׁב בְּאֵיתָן קַשְׁתּוֹ וְגוֹ׳ מִשָּׁם רֹעֶה אֶבֶן יִשְׂרָאֵל״. וְרַבּוֹתֵינוּ זִכְרוֹנָם לִבְרָכָה הִסְכִּימוּ לָזֶה, שֶׁאָמְרוּ (סוטה ד:) ״כָּל הַבָּא עַל אֵשֶׁת אִיש לְסוֹף מְבַקֵּשׁ כִּכָּר לֶחֶם וְאֵינוֹ מוֹצֵא״ וְכוּ׳, וְאִלּוּ לֹא הָיִיתִי בֵּין שְׁטוּפֵי זִמָּה אוּלַי הָיָה נִבְחָר אִישׁ אַחֵר לְתִקּוּן שְׁנֵי הָרָעָב, אֲבָל מֵאַחַר שֶׁנִּזְדַּמֵּן לִי שֶׁנִּמְכַּרְתִּי לְעַם שְׁטוּפֵי זִמָּה, לֹא זָכָה שׁוּם אֶחָד מֵהֶן לְתַקֵּן הָרָעָב כִּי אִם אֲנִי. וְאִם כֵּן הַמְּכִירָה הֵנָּה לְמִצְרַיִם גָּרְמָה לִי כִּי לְמִחְיָה שְׁלָחַנִי אֱלֹהִים לִפְנֵיכֶם.
Is my father still alive, etc. Even though they had already told him that he was alive, as is clear from all of Judah’s words, nevertheless, Joseph thought that perhaps they said this only to arouse his mercy for the old man and to prevent him from causing his death, since his soul was bound up with his [Benjamin’s] soul. Therefore, he asked them a second time Is my father still alive? But their hearts interpreted it differently — they thought that he wasn’t actually asking whether he was alive or not, but rather that he was reminding them of their sin. This is why he said my father is still alive, emphasizing that he was his father and not their father, as if to say they hadn’t shown concern for his anguish as though he wasn’t their father. Therefore, they were dismayed and could not answer him. And another reason for this panic: Because he said I am Joseph without mentioning “your brother,” they were therefore terrified and trembled, seized with fear. For they said perhaps he seeks to be an enemy and take revenge, having removed himself from brotherhood just as they had done to him when they removed themselves from brotherhood, as Rashi explained on the verse they have departed from here (Genesis 37:17). Therefore, he said to them a second time I am Joseph your brother, whom you sold to Egypt. Even though you could have at least sold me to some other nation that wasn’t so steeped in sexual immorality, nevertheless I am your brother and do not be distressed that you sold me here to Egypt, for God sent me here for sustenance. For I see that things were orchestrated such that I came among those steeped in sexual immorality, and the incident with Potiphar’s wife occurred where I conquered my inclination, and through this I merited to become Israel’s shepherd, providing and sustaining. As it is written His bow remained taut… from there he became a shepherd, a stone of Israel (Genesis 49:24). And our Sages agreed with this, saying (Sotah 4b) “Anyone who commits adultery will ultimately seek a loaf of bread and not find it.” And if I had not been among those steeped in sexual immorality, perhaps another person would have been chosen to remedy the years of famine. But since it happened that I was sold to a people steeped in sexual immorality, none of them merited to remedy the famine except me. Therefore, being sold here to Egypt caused that God sent me before you for sustenance.