וְהָיוּ֙ שְׁמֹנָ֣ה קְרָשִׁ֔ים וְאַדְנֵיהֶ֣ם כֶּ֔סֶף שִׁשָּׁ֥ה עָשָׂ֖ר אֲדָנִ֑ים שְׁנֵ֤י אֲדָנִים֙ שְׁנֵ֣י אֲדָנִ֔ים תַּ֖חַת הַקֶּ֥רֶשׁ הָאֶחָֽד׃
And there were eight boards, and their sockets of silver, sixteen sockets: under every board two sockets.
Read midrashic interpretation of Exodus 36:30: and classical rabbinic exegesis.