Exodus 24:8-10

Young's Literal Translation

⁸ And Moses taketh the blood, and sprinkleth on the people, and saith, `Lo, the blood of the covenant which Jehovah hath made with you, concerning all these things.'

⁹ And Moses goeth up, Aaron also, Nadab and Abihu, and seventy of the elders of Israel,

¹⁰ and they see the God of Israel, and under His feet [is] as the white work of the sapphire, and as the substance of the heavens for purity;