"Shalom" is the most-used Hebrew greeting in the world, but it is not just "hello." Its root means wholeness, completeness, fullness — peace not as the absence of conflict but as the presence of everything God intends.
"Selah" appears 71 times in the Psalms and 3 times in Habakkuk, but the Bible never tells us what it means. The two most careful traditional readings — "pause and reflect" and a musical instruction — are both worth holding.
"Hosanna" is a Hebrew prayer — "save now!" — that became a shout of praise. A look at its origin in Psalm 118, the Jewish feast where it became a song, and what the crowd was actually saying when they cried it as Jesus entered Jerusalem.
"Hallelujah" is a Hebrew imperative — a command to praise the LORD. It is composed of two parts: hallelu (praise ye) and Yah (the shortened form of God's personal name). When we sing it, we are calling each other to praise the God who named Himself to Moses.
"Amen" is the most universal word in the Christian and Jewish worlds, used by billions of people in every language. The Hebrew root means "to be firm, faithful, trustworthy" — and that meaning carries through every time we say it.