4 Moreover lie on your left side, and lay the iniquity of the house of Israel on it; according to the number of the days that you shall lie on it, you shall bear their iniquity. 5 For I have appointed the years of their iniquity to be to you a number of days, even three hundred ninety days: so you shall bear the iniquity of the house of Israel. 6 Again, when you have accomplished these, you shall lie on your right side, and shall bear the iniquity of the house of Judah: forty days, each day for a year, have I appointed it to you.
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.