Flavius Josephus, The Wars of the Jews
William Whiston, A.M., Ed.

[307] Nor did the Samaritans escape their share of misfortunes at this time; for they assembled themselves together upon file mountain called Gerizzim, which is with them a holy mountain, and there they remained; which collection of theirs, as well as the courageous minds they showed, could not but threaten somewhat of war; nor were they rendered wiser by the miseries that had come upon their neighboring cities. They also, notwithstanding the great success the Romans had, marched on in an unreasonable manner, depending on their own weakness, and were disposed for any tumult upon its first appearance. Vespasian therefore thought it best to prevent their motions, and to cut off the foundation of their attempts. For although all Samaria had ever garrisons settled among them, yet did the number of those that were come to Mount Gerizzim, and their conspiracy together, give ground for fear what they would be at; he therefore sent I thither Cerealis, the commander of the fifth legion, with six hundred horsemen, and three thousand footmen, who did not think it safe to go up to the mountain, and give them battle, because many of the enemy were on the higher part of the ground; so he encompassed all the lower part of the mountain with his army, and watched them all that day. Now it happened that the Samaritans, who were now destitute of water, were inflamed with a violent heat, (for it was summer time, and the multitude had not provided themselves with necessaries,) insomuch that some of them died that very day with heat, while others of them preferred slavery before such a death as that was, and fled to the Romans; by whom Cerealis understood that those which still staid there were very much broken by their misfortunes. So he went up to the mountain, and having placed his forces round about the enemy, he, in the first place, exhorted them to take the security of his right hand, and come to terms with him, and thereby save themselves; and assured them, that if they would lay down their arms, he would secure them from any harm; but when he could not prevail with them, he fell upon them and slew them all, being in number eleven thousand and six hundred. This was done on the twenty-seventh day of the month Desius [Sivan]. And these were the calamities that befell the Samaritans at this time.