What do we learn from "Mone'a Bar Yikvuhu Le'om"?
Sanhedrin 92a #1: Even fetuses curse one who refrains from teaching a Halachah to a Talmid. Le'om is a fetus - "u'Le'om mi'Le'om Ye'ematz" (Bereishis 25:23).
Sanhedrin 92a #2: One who refrains from teaching a Halachah to a Talmid will be punctured like a sieve. Yikvuhu is like "va'Yikov Chor b'Dalto" (Melachim II, 12:10).
Rosh (Bereishis 42:1): "Mone'a Bar" is Pharaoh, who hid the grain in the years of hunger; people cursed him.
Orchos Tzadikim (Sha'ar ha'Tzaikanus, DH ha'Tzaikanus): The worst evil is stinginess with one's Chachmah and Seforim. He does not lose anything [via sharing them with others]! Chachmah is like a fire; it does not lack anything if other fires are lit from it.
Malbim: This is connected to verse 25. One who refrains from selling grain, since he wanted to hoard Peros and inflate prices, people will die from hunger. The nation's curse will come on him.
Malbim (according to Mashal): One who refrains from teaching Chachmah and Torah, the nation curses him. Le'om is a nation with a creed, unlike an Am.
Why does it say "u'Vrachah l'Rosh Mashbir"?
Sanhedrin 92a: If one taught a Talmid, he merits blessings like Yosef.
Rosh (Bereishis 42:1): This refers to Yosef, who fed the world, like a shepherd conducts his flock; he is blessed. David said "Noheg ka'Tzon Yosef Yoshev ha'Keruvim Hofi'ah" (Tehilim 80:2) - when there was a famine, David asked Hashem 'conduct Your flock like Yosef, who fed the world at a time of famine.'
Malbim: One who feeds people in famine year, Brachos will come on his head.
