Right click on the time or date it was posted and copy that link/url. The time/date is usually below the persons name or the photo. It’ll say something like, “8 minutes ago” or “Yesterday” or the date and time if it’s been more than a couple days.
![facebook wall post link](https://antranik.org/wp-content/uploads/2012/12/facebook-wall-post-link.png)
Hope that helps!