The Greek noun damalis refers to a young cow — a heifer — and appears in the New Testament only in Hebrews 9:13 in the context of the red heifer ritual (Numbers 19). The word carries the technical theological weight of purification rites.
The red heifer ritual (Numbers 19) was among the most enigmatic of Israel's purification laws: the ashes of an unblemished heifer mixed with water cleansed those defiled by contact with death. The author of Hebrews uses this as a lesser-to-greater argument: if the blood of goats, bulls, and the ashes of a heifer sanctify for external, bodily cleanliness, 'how much more will the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify our conscience from dead works to serve the living God' (Hebrews 9:13–14). The heifer points beyond itself to Christ's definitive, inward purification.