Add Post Thumbnail to Feed in Wordpress

Add Post Thumbnail to Feed

//Add Post Thumbnail to Feed
function feedFilter($query) {
  if ($query->is_feed) {
		add_filter('the_content', 'feedContentFilter');
		}
	return $query;
}
add_filter('pre_get_posts','feedFilter');
 
function feedContentFilter($content) {
	$thumbId = get_post_thumbnail_id();
 
	if($thumbId) {
		$img = wp_get_attachment_image_src($thumbId);
		$image = '<img align="left" src="'. $img[0] .'" alt="" width="'. $img[1] .'" height="'. $img[2] .'" />';
		echo $image;
	}
 
	return $content;
}