Charles Ellicott Commentary Ecclesiastes 11:2

"Give a portion to seven, yea, even unto eight; for thou knowest not what evil shall be upon the earth." — Ecclesiastes 11:2 (ASV)

To seven, and also to eight. —Quite similar forms of expression occur in Job 5:19; Proverbs 30:21; Amos 1:3; Micah 5:4. The numbers seven and eight are used indefinitely in the advice to multiply our modes of exertion, ignorant as we are which may miscarry.