Who said to hell allegiance vows to the blackest devil Conscience and grace to the profoundest pit?

The quote "To hell allegiance vows to the blackest devil, Conscience and grace to the profoundest pit" is from William Shakespeare's play "Henry V." It is spoken by the character King Henry V in Act 3, Scene 1. This line reflects Henry's fierce rejection of loyalty to anything that would compromise his moral integrity, emphasizing the conflict between duty and conscience.