וְסַבֹּתֶ֣ם אֶת־הָעִ֗יר כֹּ֚ל אַנְשֵׁ֣י הַמִּלְחָמָ֔ה הַקֵּ֥יף אֶת־הָעִ֖יר פַּ֣עַם אֶחָ֑ת כֹּ֥ה תַעֲשֶׂ֖ה שֵׁ֥שֶׁת יָמִֽים׃
And ye shall compass the city, all the men of war, going about the city once. Thus shalt thou do six days.
Read kabbalistic (mystical) interpretation of Joshua 6:3: and classical mystical sources.