How to validate routes if a user is admin or not?

//This is the middle ware
public function handle($request, Closure $next)
{

        if(auth()->user()->isAdmin())   //isAdmin is a function in the User model which checks if the user is admin or not
        {
            return redirect('/admin');
        } else {
            return redirect('/home');
        }

    return $next($request);
}
//I already registered this middleware in kernel as well as verifyUser

Route::middleware(['auth', 'verifyUser'])->group(function() { 

Route::get('/home', 'HomeController@index')->name('home');

Route::get('/admin', 'AdminController@index')->name('admin');

Route::get('/users/profile', 'UserController@view')->name('users.view-profile');

Route::get('/users/edit_profile', 'UserController@edit')->name('users.edit-profile');
});

Th main problem here is it shows this error in the browser The page isn’t redirecting properly

Firefox has detected that the server is redirecting the request for this address in a way that will never complete.

This problem can sometimes be caused by disabling or refusing to accept cookies.

via Chebli Mohamed