bbp_get_reply_revisions( int $reply_id )

function bbp_get_reply_revisions( $reply_id = 0 ) {
	$reply_id  = bbp_get_reply_id( $reply_id );
	$revisions = wp_get_post_revisions( $reply_id, array( 'order' => 'ASC' ) );

	return apply_filters( 'bbp_get_reply_revisions', $revisions, $reply_id );
}