$re = '/\d[,\d]*(?=\s*visits)/is';
$str = '<meta name="description" content="‎ST. Eye Clinic - عيادة دكتور محمد عزب لطب و جراحة العيون‎, Dumyat Al Jadidah, Dumyat, Egypt. 20,956 visits ·
<meta name="description" content="ABC. 2,894,865 visits ·';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php