Say is a commandline interface to the text-to-speech system built into Darwin/OS X. It will speak files specified on the command line, or text piped into it. Say allows the user to choose which voice to use, as well as change the pitch and rate that the speech is spoken.
To utter or express in words; to tell; to speak; to declare; as, he said many wise things.
To announce as a decision or opinion; to state positively; to assert; hence, to form an opinion upon; to be sure about; to be determined in mind as to.