The Hebrew noun eshshab (H800) is a variant or construct form related to esh (H784, fire) and refers to an offering made by fire — a sacrificial offering consumed on the altar. It appears in Levitical legislation to describe the category of burnt offerings and other sacrifices presented to God through fire.
The fire-offering (eshshab) is tied to the theology of the altar as the place where the holy and the human intersect. Fire in the Old Testament represents both God's consuming holiness (Deuteronomy 4:24 — 'the LORD your God is a consuming fire') and His purifying presence. The ascending smoke of offerings was described as 'an aroma pleasing to the LORD' (Leviticus 1:9), symbolizing the worshiper's desire for the gift to reach God. Paul reinterprets this language for Christian sacrifice: 'a fragrant offering and sacrifice to God' (Ephesians 5:2) applied to Christ's atonement, and believers' bodies as 'living sacrifices' (Romans 12:1) — the New Covenant fulfillment of the fire-offering.