וְקוֹל֙ כַּנְפֵ֣י הַכְּרוּבִ֔ים נִשְׁמַ֕ע עַד־הֶחָצֵ֖ר הַחִיצֹנָ֑ה כְּק֥וֹל אֵל־שַׁדַּ֖י בְּדַבְּרֽוֹ׃
And the sound of the wings of the cherubim was heard even to the outer court, as the voice of God Almighty when He speaketh.
Read kabbalistic (mystical) interpretation of Ezekiel 10:5: and classical mystical sources.