59 Grk “but he had a rebuke.”
60 The Greek word ἄφωνος (aphōnos) means “mute, silent” or “incapable of speech.” For reasons of English style the word “dumb” was used in the translation. Despite the potential for misunderstanding (since “dumb” can refer to a lack of intellectual capability) more dynamic glosses were judged to be inelegant.
61 Grk “a voice of a (man/person).”
62 Balaam’s activities are detailed in Num 22–24 (see also Num 31:8, 16).

In other versions

but was rebuked for his own transgression; a speechless donkey spoke with human voice and restrained the prophet’s madness.

But he was rebuked for his wrongdoing by a donkey—an animal without speech—who spoke with a human voice and restrained the prophet’s madness.

but received a rebuke for his lawlessness: A speechless donkey spoke with a human voice and restrained the prophet’s madness.

But Balaam was stopped from his mad course when his donkey rebuked him with a human voice.

but received a rebuke for his own lawlessness: a speechless donkey, speaking with a human voice, restrained the prophet’s madness.

But was rebuked for his iniquity: the dumb ass speaking with man’s voice forbad the madness of the prophet.

Public Domain