4 "Then lie upon your left side, and I will lay the punishment of the house of Israel upon you; for the number of the days that you lie upon it, you shall bear their punishment. 5 For I assign to you a number of days, three hundred and ninety days, equal to the number of the years of their punishment; so long shall you bear the punishment of the house of Israel. 6 And when you have completed these, you shall lie down a second time, but on your right side, and bear the punishment of the house of Judah; forty days I assign you, a day for each year.
Matthew Henry's Commentary on Ezekiel 4:4-6
Commentary on Ezekiel 4:1-8
(Read Ezekiel 4:1-8)
The prophet was to represent the siege of Jerusalem by signs. He was to lie on his left side for a number of days, supposed to be equal to the years from the establishment of idolatry. All that the prophet sets before the children of his people, about the destruction of Jerusalem, is to show that sin is the provoking cause of the ruin of that once flourishing city.