In Animal Farm by George Orwell, why does Major ask the animals to meet in the barn after Mr. Jones has gone to sleep?

wants
to gather all the animals together in the barn so he can give them an inspiring speech. He
doesn't have much longer to live and so it's a matter of urgency that he deliver the speech as
soon as possible. Once Mr. Jones is fast asleep and all the animals have been gathered together,
Old Major launches into his speech, which is nothing less than a...