In the Summer of 326, Alexander's men refused to join their king in his attempt to reach the Ganges valley. An officer named Coenus spoke on behalf of the soldiers. The mutiny is described by the Greek author Arrian of Nicomedia in his Anabasis 5.28.1b-29.1.
The translation was made by M.M. Austin.
Mutiny at the Hyphasis
[5.28.1b] Alexander for the moment was annoyed at Coenus' plain talking and at the lack of courage of the other leaders, and dismissed the meeting.
[5.28.2] Then he summoned again the same men for the next day and angrily declared that he was going to pursue his advance, but would not compel any Macedonian to follow him against his will; for he would have men to follow their king of their own volition; as to those who wanted to return home, it was open for them to do so and report back that they had returned leaving their king in the midst of enemies.
[5.28.3] With these words he withdrew to his tent and would not admit to his presence any of his Companions for the whole of that day and for another two days after. He expected that the Macedonians and the allies would experience a change of mind, as often happens in a crowd of soldiers, and would then be more easily brought over to his point of view.
[5.28.4] But when there was profound silence through the camp and it was clear they were annoyed with his show of temper, though not prepared to change their minds because of it, then, according to Ptolemy the son of Lagus, he nonetheless offered sacrifice to cross the river, but did not obtain favorable omens.
[5.28.5] At this he called together the eldest of his Companions and especially those who were closest to him, and since everything was now pointing to withdrawal, he declared to the army that he had decided to turn back.
[5.29.1] At this there arose a loud shout such as you would expect from a large and joyful multitude, and many of them wept. Some drew near the royal tent and called for many blessings on Alexander, since he had allowed himself to be defeated by them and them alone. Then he divided the army into twelve parts and gave orders to build twelve altars, as high as the biggest towers and broader even than towers would be. These were meant as thank offerings to the gods for having brought him victorious so far, and as memorials of his labors.