What the Bible says about Seven or Eight as Many
(From Forerunner Commentary)
To paraphrase, Solomon is saying, "Okay, you are committed. Be enthusiastic and generous in your commitment." We need to invest everything we have in this life of faith.
The phrase seven or eight means "many," not just these specific numbers.
John W. Ritenbaugh
Ecclesiastes and the Feast of Tabernacles (Part 2)