Bhante Vimalaramsi discusses the very deep sutta Mn 138 Uddesa-Vibhanga Sutta:Exposition of a Summary.
The Buddha gives the monks a deep statement to contemplate but it is too much for them so they seek out Mahakaccana who explains to the the meaning of material form and what it is the cause of.
Recorded June 27, 2018 at DSMC www.dhammasukha.org