The Book of Tobit 6:4 Kommentar

Then the angel of the Lord said to him, "Gut this fish, etc." The Lord gutted the fish when He revealed the devil's wickedness more broadly to the saints, and as if eviscerated the hidden schemes of his plots. He kept the heart for Himself, because He wrapped up his cunning in the holy books; about which it is written, "Now the serpent was more cunning than any beast of the field" (Gen. III). And Paul also said of this heart: "For we are not ignorant of his designs" (II Cor. II). He also kept the gall, because He wanted it to be written and preserved how furiously he raged against the human race for the sake of caution. He also kept the liver, because He deigned to make known to us, through the doctors of truth, the devil's malicious plans against us. They say that by the heat and power of the liver, the hidden parts of consumed food are digested and reach the stage of digestion. When we diligently inquire by careful thought how the things we intend to do should be accomplished, it is as if we digest the food taken into the stomach by the heat of the liver.

These things are necessary for useful medicines. The cunning and malice of the devil, the ancient enemy, known to us, help towards healing; for the more we thoroughly investigate them, the more cautiously we avoid them.