Ecclesiastes 3:22 asks who can see what comes after death, directly echoing the uncertainty about a future heir's wisdom in 2:19.

Ecclesiastes 1:3 asks what gain there is from all labor — verse 19 answers: none, because you leave it to an heir you don't know.

Ecclesiastes 1:2 provides the refrain 'vanity of vanities' that verse 19 echoes — everything is meaningless, including labor for an unknown heir.

1 Kings 12:14-20 shows Rehoboam acting foolishly, causing the kingdom to split—a concrete example of the feared foolish heir.

1 Kings 14:25-28 records Rehoboam losing the temple treasures to Shishak, illustrating how a foolish successor squanders inherited wealth.

2 Chronicles 10:13-16 retells Rehoboam's harsh response leading to Israel's revolt—another instance of a foolish heir ruining the legacy.

2 Chronicles 12:9 records Shishak taking Jerusalem's treasures, reinforcing that a foolish heir can lose all that was built.

2 Chronicles 12:10 describes Rehoboam replacing gold shields with bronze, a diminished legacy that fits the fear of an unwise successor.

2 Chronicles 33:3 recounts Manasseh rebuilding high places Hezekiah tore down — a fool undoing a wise father's reforms.

Psalm 49:10 states that both wise and foolish die and leave wealth to others — directly paralleling the futility of laboring for an unknown heir.

In Job 21:21, the wicked man cares nothing for his family after death — contrasting with the Preacher's anxious uncertainty about his heir.

Job 14:21 echoes the same helpless ignorance: a dead person cannot know if his children are honored or shamed — just as the living cannot know the heir's character.

Exodus 1:8 shows a new king who did not know Joseph — an example of a fool inheriting the fruit of wise labor, mirroring the Preacher's fear.

2 Chronicles 10:14 shows Rehoboam's foolish counsel — a direct example of a fool inheriting from wise Solomon and causing disaster.

2 Chronicles 6:10 has Solomon wisely fulfilling David's legacy — a counterexample to the Preacher's fear of a foolish heir.

1 Kings 14:26 describes Shishak plundering treasures — illustrating how a foolish heir (Rehoboam) loses accumulated wealth, fulfilling the Preacher's worry.

1 Samuel 8:3 records Samuel's corrupt sons — a case of a wise man's legacy spoiled by unworthy successors, echoing Ecclesiastes' vanity.

Proverbs 10:1 associates a wise son with joy and a foolish son with grief — the very uncertainty the Preacher laments about his heir.

Proverbs 17:25 warns that a foolish son brings grief — the specific fear behind the Preacher's 'who knows if he will be a fool?'

Proverbs 19:13 says a foolish child ruins a father — reinforcing the anxiety that the heir might cause ruin instead of benefiting from the labor.

Proverbs 23:24 promises joy from a wise son — the hopeful alternative to the fool, highlighting what the Preacher cannot know.