What are the implications of "u'Lehoros es B'nei Yisrael"?
Rashi: It comes to incorporate in the previous Isur a Rav issuing rulings after drinking having drunk wine. 1
Shevu'os, 13b: The Torah adds "Lehoros" to "Lehavdil" to teach us that 'whoever separates from his wife close to her period will have children who are fit to Pasken. 2
Though it is not subject to Misah, based on the Pasuk in Bamidbar 18:1, "ve'Atah u'Vanecha Itach Tis'u es Avon ha'Mikdash" precludes a Rav.
See Torah Temimah, note 22.
What is the end of the Pasuk "Eis Kol ha'Chukim ... " coming to add?
Why does the Torah incorporate a prohibition against issuing rulings after drinking wine?
Seforno: Because wine captivates a person's heart, causing him to forget. 1
As the Pasuk writes in Mishlei, 31:5. Refer also to 10:9:1:2**.