Charles Ellicott Commentary Leviticus 26:40

"And they shall confess their iniquity, and the iniquity of their fathers, in their trespass which they trespassed against me, and also that, because they walked contrary unto me," — Leviticus 26:40 (ASV)

If they shall confess their iniquity. — Better, And they shall confess, that is, when their sufferings have reached this terrible point, the Israelites will realize and confess their iniquities and those of their fathers. These fathers perished in these terrible punishments because of their sins and are no longer alive to confess their sins themselves. The whole description is present to the Lawgiver’s mind; hence, the different degrees of the sins, the various stages of the sufferings, and the ultimate penitence of the people are described as passing before our eyes, as if exhibited in a kaleidoscope.

With their trespass which they trespassed against me. — Better, because of their trespass that they have, etc., as this phrase is rendered in the Authorized Version in Daniel 9:7.