Nobody knows what “selah” means.

SELAH si'lɑ, 'seɪ.lɔ, 'si.lɔ verb. Term occurring 71 times in Psalms and thrice in Habakkuk. Probably a musical direction, but meaning unknown.

2. [excl. in popular Christian culture] Amen; or some form of blessing, greeting, or praise.

There’s a friend of mine who loves to end her emails with “Selah.” Just for fun, I started ending my emails to her with “Callay”—a word from Lewis Carroll’s “Jabberwocky,” apparently said in celebration, but like selah we don’t precisely know its meaning, ’cause Carroll was deliberately being silly.

Last month she finally asked about it: “What’s ‘callay’ mean?”

“Same as ‘selah,’ ” I replied.

She didn’t inquire further. I’m guessing she thinks she knows what selah means, so she just accepted my explanation. A lot of folks who use selah think they know its meaning. It means amen, right? It’s a declaration of support, agreement, truth, joy… something positive. It’s why they put it in all the reggae songs.

Well, it may mean something positive. We don’t know.

No, seriously. We don’t know. Whatever it means, we lost its definition before the bible was translated into Greek in the second century BC. The Septuagint translates it diá-psalma/“having to do with a psalm.” Yep. Even they didn’t know what it meant—and they knew ancient Hebrew.

Oh, there are theories. The Brown-Driver-Briggs Lexicon and Theological Wordbook of the OT (which is based on that lexicon, so don’t think of it as an independent authority) deduce it means “lift up” or “exalt.” They figure this based on the ways Jews and Christians have used it through history. The similar word salá means to make light, toss aside, or balance; so it could mean something we pick up.

But when we come across it in Psalms and Habakkuk, it’s just a musical instruction. Since it’s regularly found in psalms specifically written for a menache’ákh/“choirmaster,” Ps 4, 9, 20, 21, 39, 44, 46, 47, 49, 52, 54, 55, 57, 59-62, 66-68, 75-77, 81, 84, 85, 88, 140, Ha 3 it might be a vocal instruction.

But which instruction? For all we know, “selah” was the cue to blast the trumpets.

If it means “hang,” must we hold the note? If it means “weigh,” does that mean sing it louder, or lower? If it means “reject,” is this a stop, or a pause? If it means “value,” does this mean it’s an extra-important line—so therefore we’re to sing it louder, or more solemn, or with more instruments, or even that we’re to repeat it like a chorus? Or might it have an entirely different meaning, one we’re not aware of, like “chorus” or “refrain” or “forte” or “pause” or any of the other notes we include on sheet music?

You see the problem: We’re guessing.

Fortunately we’re not trying to duplicate the psalms’ musical performances. If we set the psalms to music, we write our own musical pieces, our own choral works; we stick our own pauses and choruses and fortes in there. Not knowing what selah means won’t affect us any. It’s not like the whole theology of a psalm can flip over, depending on how Christians translate selah. It’s a direction for the choirmaster. Not for us.