The significance of the repetition of the word holy can be easily missed. It represents a peculiar literary device that is found in Hebrew forms of literature, especially in poetry. The repetition is a form of emphasis. When we want to emphasize the importance of something in English we have several devices to choose from. We may underline the important words or print them in italics or boldface type. We may attach an exclamation point following the words or set them off in quotation marks. These are all devices to call the reader’s attention to something that is especially important.
The Old Testament Jew also had different techniques to indicate emphasis. One such device was the method of repetition. We see Jesus’ use of repetition with the words, “Truly, truly, I say unto you.…” Here the double use of truly was a sign that what He was about to say was of crucial importance. The word translated “truly” is the ancient word amen. We normally think of the word amen as something people say at the end of a sermon or of a prayer. It means simply, “It is true.” Jesus used it as a preface instead of a response.
A humorous use of the repetition device may be seen in Genesis 14. The story of the battle of the kings in the Valley of Siddim mentions men who fell in the great tar pits of the region. Some translators call them asphalt pits, or bitumen pits, or simply great pits. Why the confusion in translation? Exactly what kind of pits were they? The Hebrew is unclear. The original text gives the Hebrew word for pit and then simply repeats it. The story speaks literally of pit pits. The Jew was saying that there are pits and there are pits. Some pits are pittier than other pits. These pits—the pit pits—were the pittiest pits of all. It is one thing to fall into a pit. But if you fall into a pit pit you are in deep trouble.
On a handful of occasions the Bible repeats something to the third degree. To mention something three times in succession is to elevate it to the superlative degree, to attach to it emphasis of super importance. For example, the dreadful judgment of God is declared in the book of Revelation by the eagle in midair who cried with a loud voice: “Woe! Woe! Woe to the inhabitants of the earth.…” Or we hear it in the mocking sarcasm of Jeremiah’s temple speech when he chided the people for their hypocrisy, by which they called out, “This is the temple of the Lord, the temple of the Lord, the temple of the Lord.”
Only once in sacred Scripture is an attribute of God elevated to the third degree. Only once is a characteristic of God mentioned three times in succession. The Bible says that God is holy, holy, holy. Not that He is merely holy, or even holy, holy. He is holy, holy, holy. The Bible never says that God is love, love, love, or mercy, mercy, mercy, or wrath, wrath, wrath, or justice, justice, justice. It does say that he is holy, holy, holy, the whole earth is full of His glory."
R.C. Sproul, The Holiness of God, p. 24-26