And behold, a man of the children of Israel came and brought near to his brothers the Midyanite woman, before the eyes of Moshe and before the eyes of all the congregation of the children of Israel; and they were weeping at the entrance of the Tent of Meeting.
Torah Temimah: Sanhedrin 82a — why they wept: the law was hidden from Moshe.
English: Why did they weep? Because Zimri said to Moshe: Son of Amram, is this one forbidden or permitted? And if you say forbidden — who permitted Yisro’s daughter to you? At that moment the law was hidden from him, and they all broke into weeping.
Narrative cause of the communal weeping in the verse.
Public challenge plus momentary loss of the halakhah produces the weeping at the Tent — the stage is set for Pinchas.