Ecclesiastes 1:18 states that more wisdom brings more grief—directly reinforcing 6:11's point that many words increase vanity.

Ecclesiastes 5:7 directly says many words lead to vanity, the same point made here about words increasing futility.

Ecclesiastes 1:2 declares all is vanity — the overarching theme that 6:11 applies specifically to many words.

Ecclesiastes 2:3-11 recounts Solomon's pursuit of pleasure and wealth, concluding all is vanity—paralleling the vanity of many words in 6:11.

In Ecclesiastes 1:17, the preacher finds pursuing wisdom is striving after wind—similar to the vanity of many words in 6:11.

Ecclesiastes 4:4 says toil from envy is vanity — similar theme of futility in human effort, like many words here.

Ecclesiastes 4:16 echoes the same futility — endless people and no lasting joy — reinforcing that many words or deeds add nothing.

Ecclesiastes 11:8 concludes 'all that comes is vanity' — reinforcing the same theme of futility in life's many experiences.

Job 7:16 calls his days vanity — same Hebrew word, but focuses on personal despair rather than many words producing vanity.

Psalm 39:6 describes human turmoil and heaping wealth for nothing — a parallel futility to many words increasing vanity.