In chapter eight of George Orwell's novel Animal Farm, which words or phrases in the last two sentences seem ironic?

Early in s
novel , after the animals have staged a revolution and taken control of the
farm, seven commandments are posted for everyone to see:

1. Whatever goes upon two legs is an enemy.

2. Whatever goes upon
four legs, or has wings, is a friend.

3. No animal shall wear
clothes.

4. No animal shall sleep in a bed.

5. No animal
shall drink alcohol.

6. No animal shall kill any other animal.

7. All animals are equal.

During the course of
the novel, various of these commandments are modified to suit the interests of the most powerful
animals.  In Chapter VIII, for instance, afterand some of the other powerful animals discover
alcohol and drink too much of it, Napoleon becomes extremely drunk. An order is quickly issued
in his name that no animal is to drink alcohol, upon pain of death. After he sobers up, however,
Napoleon thinks better of this directive.  The final paragraph of Chapter VIII reads as
follows:

But a few days later Muriel, reading over the Seven Commandments to
herself, noticed that there was yet another of them which the animals had remembered wrong. They
had thought the Fifth Commandment was €˜No animal shall drink alcohol,' but there were two words
that they had forgotten. Actually the Commandment read: €˜No animal shall drink alcohol to
excess.

This paragraph is doubly ironic: the statement that the animals had
remembered the fifth commandment incorrectly is false, and so, of course, is the new phrasing of
that commandment.  Once again, the commandments have been altered to suit the interests of the
farms rulers, especially Napoleon. The altering of the fifth commandment is yet more evidence of
the cynicism of Napoleon and the corruption of his regime.