Selah is one of those curious terms that is found in the Bible. It is a term that we researched when we founded Selah Mountain Ministries  in Albuquerque, New Mexico. I would like to share with you what we found and encourage you to open your Bible as I answer the question: What does Selah mean?
Psalm 66:4 “All the earth shall worship thee, and shall sing unto thee; they shall sing to thy name. Selah. “
Selah from the Hebrew
The Strong’s concordance lists the following to define Selah: 
5541: celah seh’-law; suspension (of music), i.e. pause.
5553: ragged rock, stony, strong hold.
From an unused root meaning to be lofty; a craggy rock, literally or figuratively (a fortress) — (ragged) rock, stone(-ny), strong hold.
5554: rock, Selah
A city in Edom. The same as cela’; Sela, the rock-city of Idumaea — rock, Sela(-h).
A correct pronunciation of the word is SEE LAH rather than a popular pronunciation of SAY LAH.
In the Bible it is almost always used as denoted by the Hebrew definition – as a pause such as at the end of a verse or the end of a Psalm. In modern times many believe it was originally a musical term placed to cause one to pause because 31 of the 39 Psalms that contain this word have a salutation “To the chief Musician”. Some say it means to pause and meditate upon what you just read or heard.
Selah and the Mountain
The first time we see the word Selah in the Bible is in 2 Kings 14:7. More correctly translated as “Sela” it refers to a strong city and even the capital city of Edom which is surrounded by mountains. The Arabic equivalent is known as “Petra”, also called so by the Greeks and in English we know it to mean rock.
The Rock in the Bible
He slew of Edom in the valley of salt ten thousand, and took Selah by war, and called the name of it Joktheel unto this day. (2 Kings 14:7)
Send ye the lamb to the ruler of the land from Sela to the wilderness, unto the mount of the daughter of Zion. (Isaiah 16:1)
Let the wilderness and the cities thereof lift up their voice, the villages that Kedar doth inhabit: let the inhabitants of the rock sing, let them shout from the top of the mountains. (Isaiah 42:11)
Who will bring me into the strong city? who will lead me into Edom? (Psalm 60:9)
The vision of Obadiah. Thus saith the Lord GOD concerning Edom; We have heard a rumour from the LORD, and an ambassador is sent among the heathen, Arise ye, and let us rise up against her in battle. (Obadiah 1:1)
Selah and a Pause
No doubt the most popular and most frequently occurring use of the word Selah is in the Psalms. It has been defined as a pause at the end of a verse or at the complete end of the Psalm . Habakkuk also uses Selah in like manner.
I am a musician and although I have never read a “Selah” in any music I would like to think that the Psalmist’s use of the word is much like what we might see as a fermata (the bird’s eye) that would be written above the bar of a measure. This would mean that you pause between measures, much like a Selah would pause between verses or chapters. The fermata is a little different than a rest in music as it has no specified length, again very similar to the Selah. Sometimes the fermata is used to bring notice to a particular note in the music. In this case the fermata is written above that particular note and the music director will signify the fermata as he holds his hands up, completely stopping the tempo. The singer or instrumentalist sustains (or holds) the note until the leader continues.
When we see a Selah in a portion of Scripture we should pause and think about what we have just read. In my head when I read “Selah” I say “think on this”. In the Scriptures Selah is used as a literary technique to cause the reader to meditate on God’s word.
Think on This in the Bible
Salvation belongeth unto the LORD: thy blessing is upon thy people. Selah. (Psalm 3:8)
O ye sons of men, how long will ye turn my glory into shame? how long will ye love vanity, and seek after leasing? Selah. (Psalm 4:2)
Put them in fear, O LORD: that the nations may know themselves to be but men. Selah. (Psalm 9:20)
Who is this King of glory? The LORD of hosts, he is the King of glory. Selah. (Psalm 24:10)
But God will redeem my soul from the power of the grave: for he shall receive me. Selah (Psalm 49:15)
Thou wentest forth for the salvation of thy people, even for salvation with thine anointed; thou woundedst the head out of the house of the wicked, by discovering the foundation unto the neck. Selah. (Habakkuk 3:13)
When you dig a little deeper, use some tools and let the Bible prove the Bible even a term as curious as Selah becomes clear. It is good to spend time in God’s word to learn about what He wants us to know. I pray that you are daily in the word because as His disciples  we must know what His word says and the only way to do that is to continue in His word (John 8:31-32). Selah!
More reading: How Do I Meditate on The Word of God? 
Resources – The Holy Bible, King James Version,  Strong, James. Online Exhastive Strong’s Concordance. Strong’s Hebrew/Chaldee & Greek dictionaries. http://lexiconcordance.com.  Josephus (Ant., IV, vii, 1). Photo by Sandra Jenkins, A View from Sandia crest, Albuquerque, NM