Regarding 17:60

[munir rana]

Dear Members of QM Forum

Salam

How do you understand the verse 17:60?

17:60
And when We told you (O Muhammad), "Indeed your Lord has encompassed the people." And We did not make the sight which We showed you except as a trial for the people, as was the accursed tree (mentioned) in the Quran. And We threaten them, but it increases not except in great transgression.

How can a thing showed to someone be a trial for others? What is the trial here-  hearing from the Prophet and believing or dis believing it?