I am specifically talking about going to war that is a mitzvah such as the wars fought while conquering Eretz Yisroel in the beginning of the Neviim and the mitzvah we have and will fulfill of ...
At the risk of being a guessing-game, I thought I'd read that before starting prayers (the beginning? The Amida?), one should take a minute to think about love for fellow Jews. Any source for this?