Delay WordPress posts from being sent to RSS feed

function delay_rss_feed($where) {
   
	global $wpdb;
    
    if ( is_feed() ) {
        $now = gmdate('Y-m-d H:i:s');
        $wait = '10';
        $device = 'MINUTE';
        $where.= " AND TIMESTAMPDIFF($device, $wpdb->posts.post_date_gmt, '$now') > $wait ";
    }
    return $where;
}

add_filter('posts_where', 'delay_rss_feed');