Sefer HaBahir

[Rabbi Berachiah continued,] "And what is Bet? As is written at the end, 'With wisdom, a house is built [יבנה]' (Provers 24:3) — 'was built' [נבנה] is not said, rather, 'he will build' [יבנה]. In the future, the Blessed Holy One will build her and adorn her two–thousandfold, beyond what she was. As we have said concerning what it was when the Torah began with Bet, it is written, 'I was with Him as an artisan, and I was a source of delight every day [יום יום]' (Proverbs 8:30) — two thousand years, that she was first [ראשית]." [They asked him,] "Two? But doesn't the text say seven? As is written, 'The light of the moon will be like the light of the sun, and the light of the sun will be sevenfold' (Isaiah 30:26).* [He replied,] "As we say, 'Just as the sun is to seven, so to, the moon is to seven.' Rather, we say, 'two thousand'."***[Ed. - some manuscripts include: 'Like the light of the seven days' of creation [בראשית]]**[Ed. - some manuscripts show "rather" ’[אלא] as a possibility instead of "I" [אנא] and "we say" [אמרינן] instead of "they said" [אמרו]. While this alternative is not universal, it makes more sense.]