Judah refers to the community of people living in exile. Their time away from the land is pictured as 40 years. This number suggests that they were like a lost generation. It recalls the generation that wandered 40 years in the wilderness because of their sin (Numbers 14:34).
The 430 days of Ezekiel’s confinement (Ezekiel 4:5) match the 430 years that Israel lived in Egypt (Exodus 12:40). This parallel suggests hope. Just as God once led his people out of Egypt, he would bring them out of exile. It points to the promise of a new exodus at the end of the exile.