Yeah. It's some kind of mutation.
It is a very similar theme to the original Star Trek episode "Requiem for Methuselah," which was by the same writer.
It does make sense scientifically too. Cells divide and divide. That’s what they do. How then does a cell then die? It’s in telomeres. Each time a cell divides small part of telomere shaves off each time.
Telomeres at end of chromosomes protect the dna from the cell structure and prevent it from clipping off the genes and causing havoc. It’s like having a cell divide and then lose chunks of information that mutate you.
Now with normal aging these telomeres shrink more and more to the point the cell just dies when it divides as the telomere is eroded.
But what if in a statistical fluke someone is born who has some condition or such that causes the telomeres to not erode each time cell divides? Or maybe it’s so thick that instead of cell dying at normal rate it is slowed say 20x or 30x. I.e. a human with life span of 80-90 can now live for 1600-1800years assuming 20x slow down of cell decay? Or assuming 25x that’s 2000y-2250y?
That’s within reach of Jesus now.
This is all possible in realm of science too if we can figure out how to protect telomeres and have it regen each time cell divides so you can live very very long or be basically immortal.
It could be possible he was injected some serum by some alien or he ate some perfect combo of foods that acted like a natural signal to cells to regen telomeres before division or whatever. Just some random chance fluke that happened when he was at near his midpoint prime around 35y old.
It’s all perfectly possible now. Scientifically