And when the young man went down to wash himself, a fish leaped out of the river, and would have devoured him.
Read Chapter 6
Bede
AD 735
And the Lord as the critical moment of death was on him “began to tremble with fear and be deeply dismayed,” not that he was greatly afraid of the devil but, through the natural frailty of the flesh, dreaded death, which “entered the world through the devil’s envy.” This is why “he also prayed that, if it were possible, the hour might pass from him, and said, ‘Abba, Father, all things are possible to you; remove this cup from me, but not what I will but what you will.’ ” - "On Tobit 6.3"
Here again the mystery of the Lord’s passion is quite obviously signified. For the huge fish, which, since it wanted to devour him, was killed by Tobias on the angel’s instructions, represents the ancient devourer of the human race, that is, the devil. When the latter desired the death of humanity in our Redeemer, he was caught by the power of the divinity. The river Tigris, which, because of its swift current, takes its name from the tiger, a very swift animal, intimates the downward course of our death and mortality. In it lurked a huge fish, inasmuch as the invisible seducer of the human race held the power of death. - "On Tobit 6.1–2"