Paragraph 151 151. Dareios being informed of this and having gathered together all his power, made expedition against them, and when he had marched his army up to Babylon he began to besiege them; but they cared nothing about the siege, for the Babylonians used to go up to the battlements of the wall and show contempt of Dareios and of his army by gestures and by words; and one of them uttered this saying: "Why, O Persians, do ye remain sitting here, and not depart? For then only shall ye capture us, when mules shall bring forth young." This was said by one of the Babylonians, not supposing that a mule would ever bring forth young.
Paragraph 152 152. So when a year and seven months had now passed by, Dareios began to be vexed and his whole army with him, not being able to conquer the Babylonians. And yet Dareios had used against them every kind of device and every possible means, but not even so could he conquer them, though besides other devices he had attempted it by that also with which Cyrus conquered them; but the Babylonians were terribly on their guard and he was not able to conquer them.
Paragraph 153 153. Then in the twentieth month there happened to Zopyros the son of that Megabyzos who had been of the seven men who slew the Magian, to this Zopyros, I say, son of Megabyzos there happened a prodigy,—one of the mules which served as bearers of provisions for him produced young: and when this was reported to him, and Zopyros had himself seen the foal, because he did not believe the report, he charged those who had seen it not to tell that which had happened to any one, and he considered with himself what to do. And having regard to the words spoken by the Babylonian, who had said at first that when mules should produce young, then the wall would be taken, having regard (I say) to this ominous saying, it seemed to Zopyros that Babylon could be taken: for he thought that both the man had spoken and his mule had produced young by divine dispensation.