'Momentaneous salvation from immediate mercy' is represented by the fiery flying serpent in the church in Isaiah 14:29. This serpent symbolizes people who adhere to the doctrine of salvation by faith alone.

It is worth looking at Divine Providence 340 to gain some more perspective on this passage: "This kind of evil is on the wing in the church whenever it believes in instant salvation by direct mercy, because this (a) leads to the destruction of religion, [because it leaves out the need for real, sustained repentance] (b) makes people feel safe, and (c) blames God for damnation.

9091. 'And it dies' means so severely that the good affection perishes. This is clear from the meaning of 'dying' as perishing; and from the meaning of 'the ox that has died from the blow struck by the other ox' as a good affection, dealt with immediately above in 9090.