'The voice of blood,' as in Genesis 4:10, signifies violence to charity. There are several passages in the Word where the word 'voice' is used for accusation, and 'blood' is used for sins, particularly hatred. Whoever holds hatred towards his brother kills him in his heart, as the Lord teaches in Matthew 5:21-22 and elsewhere.

(Odkazy: Arcana Coelestia 375)

375. 'A voice crying out' and 'the voice of a cry' are expressions commonly used in the Word and are applied to any situation involving any kind of uproar, commotion, or disturbance, even when the occasion is a happy one, as in Exodus 32:17-18; Zephaniah 1:9-10; Isaiah 65:19; Jeremiah 48:3. In this instance the voice is one of accusation.