"And Leah said, God has given me my reward" (Genesis 30:18). Issachar was ninth among the tribes, yet he brought his offering second before the king, as it is said, "On the second day Nethanel son of Zuar offered" (Numbers 7:18). Why? Because he was a man of Torah. This is what is written, "And of the children of Issachar, men who had understanding of the times" (1 Chronicles 12:33) - for the intercalations of the calendar. "Their heads were two hundred" - two hundred heads of Sanhedrins did the tribe of Issachar produce, "and all their brethren were at their command" - they would settle the law according to their word, and he would answer them with a law given to Moses at Sinai. And from where did all this praise come to him? From Zebulun, who occupied himself with commerce and fed Issachar, who was a man of Torah. This is what is written, "Zebulun shall dwell at the haven of the seas" (Genesis 49:13). And when Moses came to bless Israel, he placed the blessing of Zebulun before Issachar, as it is written, "Rejoice, Zebulun, in your going out, and Issachar, in your tents" (Deuteronomy 33:18) - meaning that there is reward in your tents. And some say: Issachar studies in the tents of Zebulun.
Issachar the Scholars Fed by Zebulun's Trade
Yalkut Shimoni on Torah 129:6
(בראשית ל יח) וַתֹּאמֶר לֵאָה נָתַן אֱלֹהִים שְׂכָרִי. יִשָּׂשכָר תְּשִׁיעִי לַשְּׁבָטִים, וְהוּא הִקְרִיב שֵׁנִי לַמֶּלֶךְ שֶׁנֶּאֱמַר "בַּיּוֹם הַשֵּׁנִי הִקְרִיב נְתַנְאֵל בֶּן צוּעָר" מִפְּנֵי מַה, שֶהָיָה בֶּן תּוֹרָה. הֲדָא הוּא דִּכְתִיב (דברי הימים א' יב, לג) "וּמִבְּנֵי יִשָּׂשכָר יוֹדְעֵי בִינָה לַעִתִּים", לְעִבּוּרִין. "רָאשֵׁיהֶם מָאתַיִם" מָאתַיִם רָאשֵׁי סַנְהֶדְרָאוֹת הָיָה שֵׁבֶט יִשָּׂשכָר מַעֲמִיד, "וְכָל אֲחֵיהֶם עַל פִּיהֶם", מַסְכִּימִים הֲלָכָה עַל פִּיהֶם וְהוּא מֵשִׁיב לָהֶם הֲלָכָה לְמשֶׁה מִסִּינַי, וְכָל הַשֶׁבַח הַזֶּה מִנַּיִן לוֹ, מִזְּבוּלוּן, שֶׁהָיָה עוֹסֵק בִּפְרַקְמַטְיָא וּמַאֲכִיל אֶת יִשָּׂשכָר שֶׁהוּא בֶּן תּוֹרָה. הֲדָא הוּא דִּכְתִיב "זְבוּלֻן לְחוֹף יַמִּים יִשְׁכֹּן". וּכְשֶׁבָּא מֹשֶׁה לְבָרֵךְ אֶת יִשְׂרָאֵל הִקְדִּים בִּרְכַּת זְבוּלוּן לְיִשָּׂשכָר. הֲדָא הוּא דִּכְתִיב (דברים לג, יח) "שְׂמַח זְבוּלֻן בְּצֵאתֶךָ וְיִשָּׂשכָר בְּאֹהָלֶיךָ" מִמַּה שֶׁיֵשׁ שָׂכָר בְּאֹהָלֶיךָ וְיֵשׁ אוֹמְרִים יִשָּׂשכָר בְּאָהֳלֵי זְבוּלוּן.