Episode 0519 - Sutta Nipata, XXXV (Padhana Sutta, III)
(Click on the above link, or here, for audio.)

Part III commentary on the Padhana Sutta, translated by Thanissaro
Bhikkhu. Mara 

approaches Gautama to prevent his efforts toward complete and
perfect enlightenment.

4 forms of Right Effort (exertion), and the means of working
through mental-emotional 'bipolarity' (excess &amp