ק֣וּמוּ סְּע֗וּ וְעִבְרוּ֮ אֶת־נַ֣חַל אַרְנֹן֒ רְאֵ֣ה נָתַ֣תִּי בְ֠יָדְךָ אֶת־סִיחֹ֨ן מֶֽלֶךְ־חֶשְׁבּ֧וֹן הָֽאֱמֹרִ֛י וְאֶת־אַרְצ֖וֹ הָחֵ֣ל רָ֑שׁ וְהִתְגָּ֥ר בּ֖וֹ מִלְחָמָֽה׃
Wstańcie, wyruszcie, a przeprawcie się przez potok Arnon! Patrz, oddaję w rękę twoję Sychona, króla Cheszbonu, Emorejczyka, i ziemię jego; pocznijże zdobywać, a wszczynaj z nim walkę!
Akeidat Yitzchak
Midrash Rabbah Numbers 19, explains the following two verses in Psalms. Psalm 37,3 reads "trust in the Lord , do good, rest on earth and nourish faith." In chapter 34,15 the Psalmist says "keep away from evil, do good, seek peace and pursue it." The Torah does not tell us to pursue mitzvot, rather ,when the opportunity arises in instances such as kan tzippor sending away the mother bird prior to taking her young, you perform the commandment that is at hand. However, when it is a question of making peace, the Torah wants us to seek out every opportunity, to pursue every avenue. Do not seek it only by sitting at home, but travel in pursuit of it. So did Israel. Though the Lord had said "begin to inherit the land, find a pretext to provoke war against it," (Deut 2,24), nevertheless Israel sent out messengers to Sichon, requesting a peaceful passage.