Does this video show 50,000 bikers crossing the Jordanian border into Israel to fight? No, that's not true: The video is at least three years old and appears to have been filmed in Syria.
The claim appeared in a video on TikTok (archived here) by @imreboros59 on October 9, 2023, under the title (translated from Hungarian to English by Lead Stories staff):
When will the war end? 50000 bikers arrived in Israel to fight! This is the border between Israel and Jordan!
This is what the post looked like on TikTok at the time of writing:
(Source: TikTok screenshot taken on Wed Oct 11 11:10:53 2023 UTC)
Using a Google Lens search (archive here), Lead Stories found the same video uploaded to Facebook on March 8, 2020, more than three years before the current Hamas-Israel conflict. According to the Facebook description (translated from Arabic to English by Google Translate), the video shows people smuggling gasoline on bikes between two Syrian provinces, Afrin and Idlib. It is visible that the bikers are carrying barrel-like items; reports are available about Syria's oil smuggling business.