Psalms 135:16 Kabbalah

פֶּֽה־לָ֭הֶם וְלֹ֣א יְדַבֵּ֑רוּ עֵינַ֥יִם לָ֝הֶ֗ם וְלֹ֣א יִרְאֽוּ׃

They have mouths, but they speak not; Eyes have they, but they see not;

Read kabbalistic (mystical) interpretation of Psalms 135:16: and classical mystical sources.