While this collection of texts focusses on Rava's use of Prov. 23.31, there are two previous rabbis who reference it:
(משלי כג, לא) כי יתן בכוס עינו יתהלך במישרים ר' אמי ור' אסי
חד אמר כל הנותן עינו בכוסו עריות כולן דומות עליו כמישור
וחד אמר כל הנותן עינו בכוסו כל העולם כולו דומה עליו כמישור
“Do not look upon the wine when it is red, when it gives its color in the cup, when it glides down smoothly [bemeisharim]” (Proverbs 23:31). Rabbi Ami and Rabbi Asi disagreed.
One said: Whoever casts his eye on his cup, i.e., is habitually drunk, all the prohibitions of those with whom relations are forbidden seem to him like level [mishor] ground. He is unaware of the pitfalls of sin and continues walking along a twisted and dangerous path.
And one said: Whoever casts his eye on his cup, the whole world seems to him like level [mishor] ground. Not only is such a person unconcerned by forbidden sexual relations, but all other prohibitions, e.g., monetary prohibitions, also seem permitted in his eyes.
א"ר יצחק מאי דכתיב (משלי כג, לא) אל תרא יין כי יתאדם אל תרא יין שמאדים פניהם של רשעים בעוה"ז ומלבין פניהם לעוה"ב
Rabbi Yitzḥak says: What is the meaning of that which is written: “Look not upon wine when it is red” (Proverbs 23:31)? Look not upon wine that reddens the faces of the wicked in this world when they drink it, and whitens their faces, i.e., embarrasses them, in the World-to-Come.
With these three earlier rabbinic opinions about this verse having been articulated, Rava uses this verse in the following four statements:
In these first two statements, Rava's use of the verse pertains to ritual use of wine and utilizes this verse for the necessitating red wine for kiddush on Shabbat [and holidays] and red wine at the Seder
This statement of Rava's is used to try to explain why wine a year or older should not be brought in ritual libations, regarding the material nature of the wine
רבא אמר אל תרא יין כי יתאדם אל תרא יין שאחריתו דם
Rava says that this is how the verse should be understood: “Look not upon wine that reddens [yitaddam]” means: Look not upon wine, as it leads to bloodshed [dam], indicating that one who drinks wine will end up committing an act of killing or will be killed because of it.
This use of the verse is Rava's only moralizing statement regarding this verse, while the other three uses speak more to the physical nature of the wine and its use in ritual performance.