When Noah recovered from his wine, he enslaved his grandson Canaan to his sons Shem and Japheth. The relationship he envisioned for his sons Japheth and Shem is spelled out in Gen 9.27:
יפת אלהים ליפת וישכן באהלי שם ויהי כנען עבד למו
Johanan bar Nappaha cites Noah's comment to support the use of the Greek language, spoken by Japheth’s son Javan, in the recitation of the Bible, the sacred book of Shem’s descendants. Shem-Tov ibn Falaquera says about this verse:
ואמרו ז"ל כי יפת אלהים ליפת רמז לחכמה יונית
[In English: Those of blessed memory said 'May Elohim expand Japheth' is a hint to Greek science] I have not found his source. Perhaps someone knows it?