Get a post of parent category (of another post)

Get a post of parent category

	<?php

		$category = get_the_category();
		// echo $category[0]->category_parent;

		$args = array(
	        'post_type'                 => 'post',
	        'post_status'               => 'publish',
	        'posts_per_page'            => 1,
	        'post__not_in' 				=> array( get_the_ID() ),
			'tax_query' => array(
				array(
					'taxonomy' 	=> 'category',
					'field' 	=> 'id',
					'terms' 	=> $category[0]->category_parent
				)
			)
	    );

		// The query
		$child_query = new WP_Query($args);

		// The loop
		if( $child_query->have_posts() ) : while ( $child_query->have_posts() ) : $child_query->the_post(); ?>

				<!-- article -->
				<article id="post-<?php the_ID(); ?>" <?php post_class('post-2'); ?>>

					<?php 

						echo "<h2>".get_the_title()."</h2>";

						echo "<div class='date'>Posted on"
								." <span>".get_the_time('F j, Y')."</span>";
						echo "</div>";

						// if ( has_post_thumbnail()) :
						// 	echo "<a href='".get_the_permalink()."' title='".get_the_title()."'>
						// 			<div class='featured_image'>";
						// 				the_post_thumbnail('large');
						// 			echo "</div>
						// 	</a>";
						// endif;

						html5wp_excerpt('html5wp_index');

					?>

				</article>
				<!-- /article -->

		<?php 

		endwhile; endif;

		wp_reset_postdata();

	?>