Charles Ellicott Commentary Isaiah 59:2

"but your iniquities have separated between you and your God, and your sins have hid his face from you, so that he will not hear." — Isaiah 59:2 (ASV)

Have separated — i.e., have become, as it were, a middle wall of partition excluding them from the Divine presence.

His face. — Better, the face. The Hebrew has neither article nor possessive pronoun, the substantive being treated almost as a proper name.