Charles Ellicott Commentary Psalms 74:4

"Thine adversaries have roared in the midst of thine assembly; They have set up their ensigns for signs." — Psalms 74:4 (ASV)

Thine enemies ... —As the text stands, understand it as: Thine enemies have roared in the midst of thine assembly, but many manuscripts have the plural, as in Psalms 74:8 (see the Note there for the meaning of the word).

For “roared,” see Psalms 22:1, Note, and compare Lamentations 2:7, where a similar scene is described. Instead of the voices of priest and choir, there have been heard the brutal cries of the heathen as they shouted at their work of destruction like lions roaring over their prey; or if, as some think, the reference in the next clause is to military ensigns, we have a picture of a wild soldiery exulting around the emblem of their triumph.

They set up their ensigns for signs. —The Hebrew for ensigns and signs is the same. Possibly the poet meant to have written some word meaning idols, but avoids it from dislike of mentioning the abominable things, and instead of places their idols as signs, writes, places their signs as signs.