In Parshas Beshalach, in “TazTav” (שמות טז:טו or Exodus 16:15) the Jews saw unidentified food and said “Man Hu! (It is Man)” since they didn’t know what the food was, they just knew it was edible and came from a unique source.
The second Modzhitzer Rebbe, Reb Shaul Yedidya Elazer Taub zt’l is credited with the following Chiddush. Take the letters מן הוא, rearrange them, and you get אמונה (Emunah, complete faith). This is a Remez that the Jews had complete Emunah to rely on food constantly coming down to them on a daily basis without being able to save an ounce.
They needed to not only rely on a fresh supply each morning, but that on Friday they would get a double portion. And there you go.