Isaiah 20:3

Walked naked and barefoot three years; not constantly, but when he went abroad among the people, to whom this was appointed for a sign. Some think it was only three days, a day being usually put for a year in prophetical scriptures, as Numbers 14:33,34 Eze 4:4-6. But although a day be put for a year, yet a year is never put for a day. A sign; either,

1. When this judgment should come, to wit, three years after this prophecy. Or,

2. How long it should continue, for three years; for some have observed that the Chaldeans spent so much time in conquering Egypt and Ethiopia.