The Two Minutes Hate is from George Orwell's Nineteen Eighty-Four.
It's the two minutes every day during which members of the ruling English Socialist Party express their hatred for enemies of "the Party," most notably Emmanuel Goldstein.
It's a cult-like ritual used to disable the people's capacity for critical thought, and whip them up into a terrifying, mob-like, fascistic uniformity of unquestioning devotion to the party.