Source

File: wp-includes/comment-template.php

function comment_excerpt( $comment_ID = 0 ) {
	$comment         = get_comment( $comment_ID );
	$comment_excerpt = get_comment_excerpt( $comment );

	/**
	 * Filters the comment excerpt for display.
	 *
	 * @since 1.2.0
	 * @since 4.1.0 The `$comment_ID` parameter was added.
	 *
	 * @param string $comment_excerpt The comment excerpt text.
	 * @param int    $comment_ID      The comment ID.
	 */
	echo apply_filters( 'comment_excerpt', $comment_excerpt, $comment->comment_ID );
}