Masos denotes intense, exuberant joy or exultation — a gladness that overflows into expression. Appearing about 17 times, it comes from the root sus (to rejoice, exult). It describes the kind of joy associated with a wedding (Isaiah 62:5), harvest celebration, or the arrival of salvation. It is stronger than ordinary contentment — it is rapturous delight.
Biblical joy is not circumstantial happiness but a deep theological reality rooted in God's saving acts. Masos captures this at its most intense. Jerusalem's masos was destroyed in the exile (Lamentations 5:15), but God promises to restore it — indeed to become Israel's masos (Isaiah 65:18–19). The New Testament counterpart is agalliasis (exultant joy) — the joy of those who see God's salvation. This joy is not escapism but the appropriate response to knowing the God who saves.