The computer which controlled the machines, Skynet, sent two Terminators back through time.
9 seconds sound clip from the Terminator 2: Judgment Day movie soundboard.
You can hear this line at 00:03:22 in the Blu-ray version of the movie.
Quote context
[...]
- The survivors of the nuclear fire called the war Judgment Day.
- They lived only to face a new nightmare...
- The war against the machines.
- The computer which controlled the machines, Skynet, sent two Terminators back through time.
- Their mission, to destroy the leader of the human resistance, John Connor, my son.
- The first Terminator was programmed to strike at me in the year 1984, before John was born.
- The second was set to strike at John himself when he was still a child.
- As before, the resistance was able to send a lone warrior, a protector for John.
[...]