Raḥûm is an intensive adjective from the root rāḥam (H7355), related to the noun reḥem (H7358, 'womb'). The connection to 'womb' is significant: God's compassion is like a mother's love for the child she has carried. The adjective appears 13 times in the Hebrew Bible, and with one exception (Psalm 112:4, of the righteous person), every use refers to God. It appears in the foundational divine self-declaration of Exodus 34:6 — 'the LORD, the LORD, the compassionate [raḥûm] and gracious God' — which becomes the most quoted divine description in the OT.
Exodus 34:6-7 is the theological cornerstone of Israel's understanding of God's character. The formula 'the LORD, compassionate and gracious, slow to anger, abounding in love and faithfulness' is cited or alluded to throughout the Hebrew Bible (Numbers 14:18; Nehemiah 9:17; Psalm 86:15; 103:8; 111:4; Joel 2:13; Jonah 4:2). God's raḥûm nature grounds his willingness to forgive sin and restore the repentant. The womb imagery suggests that God's compassion, like a mother's love, is instinctive, fierce, and not easily extinguished. Isaiah 49:15 uses exactly this comparison: 'Can a mother forget the baby at her breast and have no compassion on the child she has borne? Though she may forget, I will not forget you!'