Often in my rabbinic career I was asked whether there are valid Biblical grounds for the refusal of certain faiths to accept blood transfusions. The verse these faiths quote is, “Be determined in not consuming the blood, for the blood is the life, and you shall not eat the blood with the flesh” (Deut. 12:23).
The Jewish answer is that this is not what the verse is saying at all. The verse says, livil’ti achol ha-dam, “you shall not eat the blood”; in a blood transfusion the blood is not eaten.
Secondly, in an emergency the commandments may be set aside (except for three: the prohibitions of idolatry, adultery and murder). If a blood transfusion is necessary in order to save life, then life takes priority.
Why then does the Torah tell us not to consume blood? Perhaps in order to prevent violence and the shedding of blood. Ibn Ezra says, “Eating blood has an evil effect on the mind of man”.
Why is the text so adamant? Because, Rashbam explains, eating blood was part of the Egyptian cult which the Israelites had seen during their years as slaves.
With the best will in the world, a Jew cannot understand why Christians regard communion wine as symbolic of Jesus’ blood and thus – at least metaphorically – imbibe their saviour’s blood.
Nor can a Jew understand how anyone could take the so-called blood libel seriously with its allegation that Jews use Christian blood to carry out the Pesach rituals.
One last question: why does the text tell us that blood is life?
Simply because the way in which the Almighty formed His creatures ensured that the blood carried the life, and the state of the blood reveals the state of one’s health.