When Golgari Rot Farm enters the battlefield, it, Sarinth Greatwurm, and Kodama of the East Tree trigger.
Resolve the Kodama of the East Tree trigger, choosing not to put anything from your hand onto the battlefield.
Resolve the Golgari Rot Farm trigger, returning it from the battlefield to your hand.
Resolve the Sarinth Greatwurm trigger, creating a token.
When the token enters the battlefield, Kodama triggers, putting Golgari Rot Farm from your hand onto the battlefield.
When Golgari Rot Farm enters the battlefield, it and Sarinth Greatwurm trigger.
Repeat from step 4.
This delightful loop turns the humble bounce land Golgari Rot Farm into an engine of endless re-entry. As the Rot Farm repeatedly enters and returns itself to your hand, the static presence of Sarinth Greatwurm watches lands arrive to continually forge tapped Powerstone tokens. Each time one of those tokens touches the battlefield, Kodama of the East Tree's triggered ability steps in, using its reach to effortlessly drop Golgari Rot Farm right back onto the battlefield from your hand to restart the cycle.