According to Talmud (Mishnah Sanhedrin 4:5; Babylonian Talmud Tractate Sanhedrin 37a),
Whoever destroys a soul, it is considered as if he destroyed an entire world. And whoever saves a life, it is considered as if he saved an entire world.
I wonder, does it apply to someone who donated blood to be used as part of a transfusion?
For the purposes of this question, lets assume:
- The blood was received by a person who would die without blood transfusion
- Giver's blood was received by chance. There is nothing specific about giver's blood other then that it was available when needed and was of right type
- Giver does not know whether blood was used to save a life or as part of a routine surgery