על חיי משה, ספר א ט״זOn the Life of Moses, Book I 16

א׳
1so, when all the magnates had collected at the palace, the brother of Moses took his staff, and, after waving it in a very conspicuous manner, flung it on the ground, where it immediately turned into a serpent, while the onlookers standing round were filled with wonder, fell back in fear, and were on the point of running away.
ב׳
2[92] But all the wizards and magicians who were present said: “Why are you terrified? We, too, are practised in such matters, and we use our skill to produce similar results.” Then, as each of them threw down the staff which he held, there appeared a multitude of serpents writhing round a single one;
ג׳
3[93] that one, the first, showed its great superiority by rising high, widening its chest and opening its mouth, when with the suction of its breath it swept the others in with irresistible force, like a whole draught of fishes encircled by the net, and, after swallowing them up, changed to its original nature, and became a staff.
ד׳
4[94] By this time, the marvellous spectacle had refuted the scepticism in every ill-disposed person’s soul, and they now regarded these events not as the works of human cunning or artifices fabricated to deceive, but as brought about by some diviner power to which every feat is easy.
ה׳
5[95] But, though they were compelled by the clear evidence of the facts to admit the truth, they did not abate their audacity, but clung to their old inhumanity and impiety as though it were the surest of blessings. They did not show mercy to those who were unjustly enslaved, nor carry out the orders which had divine authority,  since God had shown His will by the proofs of signs and wonders, which are clearer than oracles. And therefore a severer visitation was needed, and volley of those blows whereby fools whom reason has not disciplined are brought to their senses.
ו׳
6[96] The punishments inflicted on the land were ten—a perfect number for the chastisement of those who brought sin to perfection. The chastisement was different from the usual kind,