"This is the thing that the LORD has commanded: gather of it" (Exodus 16:16-18). They said: now Nachshon son of Amminadab and his household will go out and gather much, and the poorest in Israel will go out and gather little, and when they come to the measure they were all found equal, as it is said, "And they measured it with an omer" and so forth. They said: one who eats this measure is healthy and blessed; less than this, he is disordered in the bowels; more than this, he is a glutton. "And the children of Israel did so": they did what they were commanded and did not transgress the decree of Moses. ("And they gathered, some more, some less, and they measured it with an omer.")
The Omer Measure That Made Rich and Poor Come Out Equal
Yalkut Shimoni on Torah 260:5
(שמות טז טז-יח) זֶה הַדָּבָר אֲשֶׁר צִוָּה ה' לִקְטוּ מִמֶּנּוּ. אָמְרוּ, עַכְשָׁיו יֵצֵא נַחְשוֹן בֶּן עֲמִּינָדָב וּבֵיתוֹ וּמְלַקֵּט הַרְבֶּה, יֵצֵא עָנִי שֶׁבְּיִשְׂרָאֵל וּמְלַקֵּט קִמְעָא, וּכְשֶׁהֵן בָּאִין לְידֵי מִדָּה נִמְצְאוּ כֻּלָּם שָׁוִים, שֶׁנֶּאֱמַר וַיָּמֹדּוּ בָעֹמֶר וְגוֹ', אָמְרוּ, זֶה שֶׁאוֹכֵל כַּשִּׁעוּר הַזֶּה הֲרֵי זֶה בָּרִיא וּמְבוֹרָךְ, פָּחוֹת מִכַּאן מְקוּלְקָל בָּמֵּעַיִם, יוֹתֵר מִכַּאן הֲרֵי זֶה רַעַבְתָּן. וַיַּעֲשׂוּ כֵן בְּנֵי יִשְׂרָאֵל. עָשׂוּ מַה שֶׁנִּתְפָּקְדוּ וְלֹא עָבְרוּ עַל גְּזֵרַת מֹשֶׁה. (וַיִּלְקְטוּ הַמַּרְבֶּה וְהַמַּמְעִיט, וַיָּמֹדּוּ בָעֹמֶר).