Verily ye pass by their (sites) by day Cf. xv. 76, and n. 1998. The tract where they lay is situated on the highway to Syria where the Arab caravans travelled regularly, "by day and by night".
https://www.islamhelpline.net/quran/37/137
And penetrate forthwith into the midst (of the foe) en masse The forces of evil mass themselves for strength, but their massing itself may become a means of their speedy undoing.
https://www.islamhelpline.net/quran/100/5