Tax Query Testimonials

$tax_query = array(
	'relation' => 'AND',
	array(
		'taxonomy'         => 'topic',
		'terms'            => '$post_term',
		'field'            => 'slug',
		'include_children' => false,
	),
	array(
		'taxonomy'         => 'testimonial-length',
		'terms'            => 'xs',
		'field'            => 'slug',
	),
);