SELECT
posts.body AS source_body,
matched_posts.body AS matched_body
FROM [bigquery-public-data:stackoverflow.stackoverflow_posts] AS posts
INNER JOIN [bigquery-public-data:stackoverflow.stackoverflow_posts] AS matched_posts
ON matched_posts.id = FIRST((
SELECT duplicates.target_id FROM (
SELECT
source_posts.id AS source_id,
related_posts.id AS target_id
FROM [bigquery-public-data:stackoverflow.post_links] AS post_links
INNER JOIN [bigquery-public-data:stackoverflow.stackoverflow_posts] AS source_posts