Βιβλιοθήκη ἱστορική 17.86.6

17.86.6

ὁ δὲ Μῶφις ὁρῶν τὴν ταραχὴν τῶν Μακεδόνων καὶ τὸ γεγονὸς συλλογιζόμενος τὴν μὲν δύναμιν κατέλιπεν, αὐτὸς δὲ μετὰ ὀλίγων προϊππεύσας καὶ τὴν ἄγνοιαν τῶν Μακεδόνων διορθωσάμενος παρέδωκεν ἑαυτόν τε καὶ τὴν δύναμιν τῷ βασιλεῖ.

Alexander having thus outwitted the Indians by these feints, obtained possession of the rock without risk being incurred. He then gave his guide the stipulated reward, and moved off with his army at the very time when Aphrikes, an Indian who had 20,000 soldiers and 15 elephants, was hovering about in that locality. This man certain of his followers put to death, and, having brought his head to Alexander, procured for this service their own safety. The king took them into his own ranks, and got possession of the elephants, which were wandering at large about the country.
He then came to the river Indus, and, finding that the thirty-oared galleys which he ordered had been prepared, and the passage bridged, he gave his army a rest of thirty days to recruit their strength. Having then offered to the gods sacrifices on a magnificent scale, he led his army over to the other side, where he met with an incident which took a strange and unexpected turn. For Taxiles being by this time dead, his son Mophis had succeeded to the government. Now Mophis had before this not only sent word to Alexander, then in Sogdiana, that he would fight on his side against any Indians who might appear in arms against him, but at this juncture had also sent ambassadors to say that he surrendered his kingdom into his hands. So when Alexander was at a distance of forty stadia he set forth to meet him, attended by his friends, and his army drawn up in battle order and his elephants ranged in line. Alexander, seeing a great host advancing towards him drawn up as if for action, thought that the Indian had treacherously offered to surrender that he might thus fall upon the Macedonians before they could prepare for battle. He therefore ordered the trumpeters to sound to arms, and, having marshalled his troops, advanced to give the Indians battle. But Mophis, on seeing the commotion in the Macedonian ranks, and comprehending its cause, left his army, and riding forward with a few of his friends, corrected the mistake into which the Macedonians had fallen, and surrendered himself and his army to the king. Alexander, to mark his approbation of this conduct, gave back his kingdom to Mophis, and ever afterwards treated him as a friend and ally. He also changed his name to Taxiles.