כִּ֣י כֹ֥ה אָמַ֛ר אֵלַ֖י אֲדֹנָ֑י לֵ֚ךְ הַעֲמֵ֣ד הַֽמְצַפֶּ֔ה אֲשֶׁ֥ר יִרְאֶ֖ה יַגִּֽיד׃
For thus hath the Lord said unto me: Go, set a watchman; let him declare what he seeth!
Read kabbalistic (mystical) interpretation of Isaiah 21:6: and classical mystical sources.