en_tn_condensed/isa/57/17.md

I hid my face

This means God gave up on his people and no longer helped or blessed them. (See: rc://en/ta/man/jit/figs-idiom)

he went backward in the way of his heart

This means the Israelites kept rejecting the true God for false ones. Here "backward" and "way" are location words representing motivations and feelings. (See: rc://en/ta/man/jit/figs-metonymy)