Ehm, afaik the return
value of the menu fn is an object
: You need to type cast
earlier
$menu_items = (array) wp_get_nav_menu_items( 26 ); // Typecast here
$menu_items = array_rand( $menu_items, 3 );
foreach ( $menu_items as $key => $menu_item )
{
echo $menu_item['title'];
}