That's all Jerry needs to hear after eavesdropping on Butch's threat to Tom. Poor Butch had been trying to take a nap and been constantly interrupted by Tom making a racket chasing Jerry around the house.
The lengths Tom goes to keep things quiet, and the things Jerry does to produce noise so that the big bulldog will wake up and beat the tar out of the cat are all very funny. There are some excellent sight gags connected with the above, many defying the law of physics!
This cartoon also featured the first time I've ever heard Tom sing a lullaby to Spike, and that was funny, too. "Go to sleep, go to sleep, close your big, bloodshot eyes," is just one of the verses he sings. "You're a dope, you're a lug, and I hope you don't wake up."
My favorite "bit" was Tom's drum solo on the out-cold dog.
This cartoon, by the way, won an Oscar. I have no arguments with that.