The physical substance of blood, representing life itself in Hebrew thought ('the life of the flesh is in the blood,' Lev 17:11). It covers bloodshed (murder, warfare), sacrificial blood (atonement rituals), the blood of the covenant, and blood-guilt. The plural dāmîm often means 'bloodshed' or 'blood-guiltiness.'
Blood is arguably the most theologically dense substance in Scripture. Its significance rests on the equation blood = life (Gen 9:4; Lev 17:11). Because life belongs to God, shedding innocent blood is the ultimate crime (Gen 4:10 — Abel's blood cries from the ground), and consuming blood is forbidden (Lev 17:12). Yet precisely because blood represents life, it becomes the means of atonement: 'It is the blood that maketh an atonement for the soul' (Lev 17:11). The Passover blood on the doorposts saved Israel from death (Exod 12:13). Moses sprinkled covenant blood on the people (Exod 24:8). Every OT sacrifice pointed forward to the 'blood of the new covenant' shed by Christ (Matt 26:28; Heb 9:22). The writer of Hebrews declares, 'Without shedding of blood is no remission' — the entire sacrificial system finds its fulfillment in the cross.