add_filter( 'comments_open', '__return_false' );
add_action( 'comment_form_comments_closed', function() {
echo '<p>Comments are temporarily closed while we perform maintenance on the website.</p>';
} );
add_filter( 'comments_open', '__return_false' );
add_action( 'comment_form_comments_closed', function() {
echo '<p>Comments are temporarily closed while we perform maintenance on the website.</p>';
} );