On Rosh Hashanah, the prosecuting forces rise up against a person. However, one is meant to first daven for the honor of Hashem on this day, and only then to daven for himself. This is seen from the verse (Iyov 2:1): “Now the day came about that the sons of G-d came to stand beside Hashem and the Adversary too came among them to stand beside Hashem.” What is relevant to Hashem comes first, and then comes what is relevant to oneself.
The best way to prepare for this day is by increasing unity amongst Klal Yisroel, as is stated (Tehillim 98:6): “With trumpets and the sound of the shofar, you shall blow (hari’u) before the King.” The word “hari’u” connotes “reyus”, brotherliness. This is also hinted to in the verse (Tehillim 96:12): “The field and all that is therein will rejoice; then all the trees of the forest will sing praises.” “Trees of the forest” can be a reference to simple, unlearned people. Thus, the pasuk is saying that they too must join with the nation in preparation for Rosh Hashanah, as unity amongst everyone is necessary.
This is hinted to in the words of the pasuk: “When a camp goes out against your enemies, you shall beware of every evil thing (daver).” This can be understood to mean that you should not say a bad word (dibbur) about anyone else and you should not see their faults. Rather, you should only speak well of them and see their good sides.
This is also seen from the verse (Tehillim 34:13): “Who is the man who desires life? Guard your tongue from evil.” Who can ask on Rosh Hashanah to be inscribed in the book of life? He who never speaks badly about his fellow Jews.
If one treats his friends this way, he is ready to face the Day of Judgment.
