Reference for Isaiah 6:3

וְקָרָ֨א זֶ֤ה אֶל־זֶה֙ וְאָמַ֔ר קָד֧וֹשׁ ׀ קָד֛וֹשׁ קָד֖וֹשׁ יְהוָ֣ה צְבָא֑וֹת מְלֹ֥א כָל־הָאָ֖רֶץ כְּבוֹדֽוֹ׃

And one called unto another, and said: Holy, holy, holy, is the LORD of hosts; The whole earth is full of His glory.