על חיי משה, ספר ב מ״טOn the Life of Moses, Book II 49

א׳
1[270] Such was his pronouncement under divine inspiration on the matter of the food which came from heaven, but there are examples to follow which must be noted, though perhaps they may be thought to resemble exhortations rather than oracular sayings. Among these is the command given at their great backsliding from the ways of their fathers, about which I have spoken above. This was when, after fashioning a golden bull in imitation of the vanity of Egypt,  they set up choirs and built altars and brought victims for sacrifice in forgetfulness of the true God and to the ruin of the high-born qualities inherited from their forefathers and fostered by piety and holiness.
ב׳
2[271] At this, Moses was cut to the heart to think that in the first place the whole people had suddenly been blinded who a few hours ago had excelled every nation in clearness of vision, and secondly, that a fable falsely invented could quench the bright radiance of truth—truth on which no eclipse of the sun or of all the starry choir can cast a shadow, since it is illumined by its own light, the intelligible, the incorporeal, compared with which the light of the senses would seem to be as night compared with day.
ג׳
3[272] He therefore became another man, changed both in outward appearance and mind; and, filled with the spirit, he cried: “Who is there who has no part with this delusion nor has given to no-lords the name of lordship? Let all such come to me.”
ד׳
4[273] One tribe came at the call, bringing with them their minds no less than their bodies, men who for some time had been breathing slaughter against the godless workers of unholiness, but sought to find a leader and captain who would have the right to tell them when and how to make this attack. When Moses found them hot with rage and brimful of courage and resolution, he was more than ever possessed by the spirit and said: “Let each of you take his sword and rush through the whole camp, and slay not only those who are strangers to you but also the very nearest of your friends and kinsfolk. Mow them down, holding that to be a truly righteous deed which is done for truth and God’s honour, a cause which to champion and defend is the lightest of labours.”
ה׳
5[274] So they slaughtered three thousand of the principal leaders in godlessness, without meeting any resistance, and thereby not only made good their defence against the charge of having been party to the shameless crime, but were accounted as the noblest of heroes and awarded the prize most suitable to their action, that is the priesthood. For it was meet that the duty of ministering to holiness should be given to those who had battled and acquitted themselves bravely in its defence.