How many days was Ezekiel told to lie on his left side, bearing Israel's iniquity?

Answer: 390

Ezekiel lay on his left side 390 days for Israel's iniquity, then on his right side 40 days for Judah, a day for each year.

“For I have assigned to you 390 days, according to the number of years of their iniquity. So you shall bear the iniquity of the house of Israel.”— Ezekiel 4:5 (BSB)