To weaken France's image, to sow chaos, to get security forces focused on other things while they try to get specific targets.
There have been reports about both Russia and Iran being potentially involved.
So far I've seen an article about a Russian getting arrested 2 days ago.
https://www.reuters.com/world/middle-east/nine-people-killed-rocket-hits-football-pitch-israeli-occupied-golan-israel-2024-07-27/