Specific sutta in the Majjhima Nikaya: Where is past and future discussed? Im looking for a specific sutta in the Majjhima Nikaya. 

In the sutta past and future is being discussed and also how a practitioner on the insight path can gain seclusion from the 5 aggregates.

Help would be much appreciated.

Lanka
A few suttas fit this, but try this first - 
Bhaddekaratta Sutta: An Auspicious Day
http://www.accesstoinsight.org/tipitaka/mn/mn.131.than.html