Everyone knows that Genesis 1 claims that God created the world in six days and rested on the seventh. William Brown (Seven Pillars of Creation) shows that the sevens are everywhere in the creation account:
“The account of Genesis 1 is carefully structured around seven days within which eight acts of creation and ten commands are listed. The number seven is no random counting. God ‘saw’ and pronounced creation ‘good’ seven times; ‘earth’ or ‘land’ (same word in Hebrew) appears twenty-one times; ‘God’ is repeated thirty-five times. The number seven, or multiples thereof, also crops up within certain discrete passages: Genesis 1:1 consists of seven words; 1:2 features fourteen words; Genesis 2:1–3 renders a word count of thirty five. In fact, the total word count of the narrative proper (1:1–2:3) is 469 in Hebrew (7 × 67)” (37).
Brown wonders why 7 so fascinated the ancients. He answers by describing some of the odd properties of the number: “The number is a perfectly odd integer. It is also oddly powerful. Mathematically, the number seven is unique in that it, along with its multiples, divides any non-divisible number with the same repetitive pattern: 1/7 = .142857142 . . . ; 2/7 = .2857142857142 . . . ; 3/7 = .42857142 . . . , with the seventh decimal position marking the return of the repeated series! The number seven bears a distinctly varied but repeated order. Repeatable variation, in fact, characterizes the text’s structure. Moreover, the number seven may derive from the seven cosmic non-stellar entities visible to the ancients, consonant with the fact that Genesis 1 is the most cosmically oriented creation text in the Hebrew Scriptures.”But he thinks that ritual concerns were more fundamental than mathematical ones: “the number seven connotes a ritual sense of completion or fulfillment. It is no coincidence, then, that creation’s completion is affirmed on the seventh day, rather than on the sixth (Gen 2:2). Marking the formal completion of all work, the seventh day is the culmination and conclusion of the Genesis account. It is not an afterthought.”