Likutei Sichos – Vol 17 p 401 ffPirkei Avos Perek 6, first Mishna.He begins the Perek קנין תורה with he who learns Torah Lishma, which seems a bit much for the opener of such a Perek.He lists a series of gains that come along with Torah Lishma using various different forms.The Rebbe explains it all:...