Rashi on Exodus 16:16/רש"י על שמות ט״ז:ט״ז

1עמר — the name of a measure.

2מספר נפשתיכם — The second half of the verse means ACCORDING TO (supply כ before מספר) THE NUMBER OF PERSONS WHOM A MAN HAS (איש לאשר being the same as אשר לאיש) IN HIS TENT SHALL YE TAKE AN OMER FOR EVERY HEAD (לַגֻּלגֹּלֶת the definite article with the ל having distributive force: each and every).