Isaiah 1:15

And when ye spread forth your hands, in a gesture which is a caricature of true prayer, I will hide Mine eyes from you, His eyes, as it were, finding themselves unable to look upon such hypocrisy; yea, when ye make many prayers, in the foolish belief that mere lip-service is sufficient before Him, I will not hear; your hands are full of blood, for the people of Jerusalem and Judah were guilty of violence and injustice before God, by which they had become murderers in His eyes. Those who do not serve the Lord in spirit and in truth also lose all true love and mercy over against their neighbor, and therefore the sighing of the afflicted becomes an obstruction between them and the Lord and hinders the effect of their prayers.