Part 1 - The brief teaching

Now there is the instruction to rely on the spiritual friend and abandon evil:

As vines that grow on a sandalwood tree assume its odor,
By relating with holy ones, we ourselves become holy.
Like kusha grass that grows within a putrid swamp,
By keeping bad company, we ourselves go bad.
Therefore sincerely try to relate with holy persons.
Also to abandon evil spiritual friends.

A vine that clings to a sandalwood tree, because of that is tall and fragrant. Kusha grass growing in filth of decayed fish and so on itself becomes nasty. Just so, having seen the benefit and harm that come from relying on holy and unholy ones, as for the instruction to rely on those who are holy, the Vinaya Scriptures say:

As a vine that relies on a sala tree
Grows to be strong with an aromatic smell,
A person who relies on the holy ones
Will be embraced by goodness and shine with splendor.

Also it says there:

When kusha grass in the neighborhood of people
Comes to be entwined with rotten fish,
And they are not kept quite far away,
The kusha will begin to be like the fish.

Similarly what people will become
Relying on bad persons is like that.