$thevoters_ids = get_post_meta( get_the_ID(), "thevoters", true ); // get a comma separated list of ids

$thevoters_ids = explode( \',\', $thevoters_ids ); // turn the list into an array

foreach ( $thevoters_ids as $thevoter_id ) { // loop through the ids
    $thevoter = get_user_by( \'id\', $thevoter_id ); // get the user object by id
    echo $thevoter->display_name; // display the user name
}