I need to modify the_post_thumbnail function to run "Lazyload" on it, i think there is two solutions :
1- modify the args to be something like this
the_post_thumbnail('product', array('data-original'=>$src, 'src'=>'grey.gif'));
2- get only the image url from the function ... i've tried alot of snippets and nothing worked for me , like this one !
$thumbnail_src = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), "size" );