וְלֹא־שָׁמְע֣וּ אֶל־מֹשֶׁ֗ה וַיּוֹתִ֨רוּ אֲנָשִׁ֤ים מִמֶּ֙נּוּ֙ עַד־בֹּ֔קֶר וַיָּ֥רֻם תּוֹלָעִ֖ים וַיִּבְאַ֑שׁ וַיִּקְצֹ֥ף עֲלֵהֶ֖ם מֹשֶֽׁה׃
Notwithstanding they hearkened not unto Moses; but some of them left of it until the morning, and it bred worms, and rotted; and Moses was wroth with them.
Read kabbalistic (mystical) interpretation of Exodus 16:20: and classical mystical sources.