NUM67 Sound trumpets when offerings are brought in the Beis HaMikdash and during wartime. When an offering is brought, the person must concentrate his thoughts on the offering and keep his mind free of thoughts that would disqualify the offering. Similarly, his intent must be to bring the offering solely for the sake of Heaven--in order to fulfill a Divine command. In times of distress, too, when we cry out to Hashem for help, begging Him to have mercy on us and save us, our minds must be clear of all unwanted thought so that our pleas for help are sincere and focused. Accordingly, Hashem commands us to blow trumpets at these times, for man is a physical being and by nature, unless he is stirred, he is close to being asleep. As is known, nothing has greater power than musical instruments to stir emotions and awaken the heart. This is especially so regarding the trumpet, the loudest musical instrument of all. During an enemy attack, when we hear a trumpet blast our hearts are stirred to turn to Hashem and forget all other concerns. So, too, when we hear a trumpet blast when an offering is brought, it helps us to forget all mundane matters and focus all of our attention upon the mitzvah at hand.