Fascinating article on slavery, here.
On דינא דבר מיצרא when the buyer is an עני, here.
Rav Kook on the avdus in Mitzraim, here.
The Lubavitcher Rebbe on the Rashi in this weeks parsha where Yosef showed Yaakov his "shtar ksuba and shtar eirusin". Amazing. Here.
Vayechi, achdus and Shmitta - here.