Exodus 38 has several incidental references to the number seven,

“All the gold that was used in all the work of the holy place, that is, the gold of the offering, was twenty-nine talents and seven hundred and thirty shekels, according to the shekel of the sanctuary. And the silver from those who were numbered of the congregation was one hundred talents and one thousand seven hundred and seventy-five shekels, according to the shekel of the sanctuary…Then from the one thousand seven hundred and seventy-five shekels he made hooks for the pillars, overlaid their capitals, and made bands for them. The offering of bronze was seventy talents and two thousand four hundred shekels” (Exodus 28.24, 25, 28, 29).

If you think those do not represent incidental references, please comment.