This rare noun denotes exceptional purity or the state of being purified. At Sinai, the elders saw beneath God's feet something like a pavement of sapphire stone, clear 'as the very heavens for purity' (Exodus 24:10)—an image of transcendent clarity. In Leviticus it also refers to the period of ritual purification after childbirth. The word captures both physical brightness and ceremonial cleanness.