Yet, after all, we are not bound to believe this legend, any more
than we are bound to believe that when Jacob saw a Persian judge
give an unjust sentence, he forthwith cursed, not him, but a rock
close by, which instantly crumbled into innumerable fragments, so
terrifying that judge that he at once revoked his sentence, and gave
a just decision.

Neither, again, need we believe that it was by sending, as men said
in his own days, swarms of mosquitos against the Persian invaders,
that he put to flight their elephants and horses: and yet it may be
true that, in the famous siege of Nisibis, Jacob played the patriot
and the valiant man. For when Sapor, the Persian king, came against
Nisibis with all his forces, with troops of elephants, and huge
machines of war, and towers full of archers wheeled up to the walls,
and at last, damming the river itself, turned its current against
the fortifications of unburnt brick, until a vast breach was opened
in the walls, then Jacob, standing in the breach, encouraged by his
prayers his fellow-townsmen to stop it with stone, brick, timber,
and whatsoever came to hand; and Sapor, the Persian Sultan, saw
"that divine man," and his goats'-hair tunic and cloak seemed
transformed into a purple robe and royal diadem. And, whether he
was seized with superstitious fear, or whether the hot sun or the
marshy ground had infected his troops with disease, or whether the
mosquito swarms actually became intolerable, the great King of
Persia turned and went away.

So Nisibis was saved for a while; to be shamefully surrendered to
the Persians a few years afterwards by the weak young Emperor
Jovian. Old Ammianus Marcellinus, brave soldier as he was, saw with