I found a solution for my question , it's simply to concat the "with:

$posts = Post::with('user') ->with(array('comments.user'=>function($query){ $query->where('created_at', '=', 1); })) ->with('tags') ->where('travel_area_id','=',$area->id) ->take($this->numOfPostsInAreaPageLoad) ->orderBy('created_at', 'DESC') ->get();

but now I would like to have an eager load constraint on "comments.user" more specifically on the comments, and not on the user, any idea how, because the current where inflects the query for the user of the comment.

AMAZING!!!!

found the solution, you should nest each one of the eager loads inside

$posts = Post::with('user')
     ->with(array('comments'=>function($query){
         $query->where('user_id', '=', 3);
         $query->with('user');
     }))
     ->with('tags')
     ->where('travel_area_id','=',$area->id)
     ->take($this->numOfPostsInAreaPageLoad)
     ->orderBy('created_at', 'DESC')
     ->get();

Hey bud, glad you could figure it out.

I don't mean to hijack your thread, but could you take a look at the post I made a couple hours ago because I think I'm struggling with a similar issue as this, but can't make sense of your answer right now.

http://laravel.io/forum/02-10-2014-creating-a-filter-for-results-from-relationships

Alternative method using dot notation:

https://laracasts.com/discuss/channels/general-discussion/nested-eager-loading-with-constraints/replies/35385

When testing:

$query->with([
    'children' => function ($q) {
        $q->where('someCol', 'someVal'); //constraint on children
    },'children.grandchildren' => function ($q) {
            $q->where('someOtherCol', 'someOtherVal'); //constraint on grandchildren
    }
]);

Use:

dd($result->first()->children->first()->grandchildren->first());

NOT:

dd($result->first()->children()->first()->grandchildren()->first());

Note the parentheses which cause the relationships to be returned as queries instead of dynamic properties. Then first() gets called on a query instead of a collection, returning a fresh database response which doesn't have the specified constraints.

I was tearing my hair out trying to figure out why my where was being skipped until I spotted the extra parentheses.