You are to weigh out twenty shekels of food to eat each day, and you are to eat it at set times.
This confirms what I have said, namely, that the want should be such, that the Prophet dared not eat even that bread to satiety: you shall eat, says he, bread by weight, viz, twenty shekels. These are not complete rounds, so that the sense is, that God commanded his Prophet to live sparingly. When the city was besieged, bread was distributed in pieces to each person.
The best exposition of this part of Ezekiel's prediction of Jerusalem's desolation is Jeremiah's lamentation of it, Lam 4:3, Lam 4:4, etc., and Lam 4:10, where he pathetically describes the terrible famine that was in Jerusalem during the siege and the sad effects of it. I.
Commenting on Ezekiel 4:9-17
And thy meat which thou shall eat shall be by weight, twenty shekels a day,.... To eat bread by weight was a sign of a grievous famine; see Lev 26:26; a shekel, according to Josephus (i), weighed four Attic drachms, or half an ounce, wherefore twenty shekels weighed ten ounces; so that the bread the prophet had to eat was but ten ounces a day...