One must take great care not to get angry on Rosh Hashana. Apart from the fact that anger is something that one has to avoid and is considered harmful at any time, on Rosh Hashana, it is actually a bad sign for a person.
From this we can learn that we have to go out of our way to avoid anger. This would include, both getting angry ourselves as well as causing others to get angry. One such example in Ben Ish Hai is, that at on the eve of Rosh Hashanah, the lady of the home should be particular to quickly set the table and cover it with a beautiful table cloth, so that when her husband comes home from Synagogue, he will find the table set. This is considered to be a Siman Tob (a good sign).
However, let's say the husband comes home and the wife was running late, (as does happen,) and the table is not set. Then he must not get into an argument with his wife and he must not get angry, because as we have already established, anger is something very negative.
On the contrary, he should not only not show any anger, but he must make sure that he does not feel any anger, and it is fair to say that this must be applied across the board to everybody in all circumstances.
(See Ben Ish Hai, Shana Aleph, Parashath Nissabeem, Oth Waw)
