def _disallow_implicit_dependencies(self):
        """Disallow seeds to take implicit upstream dependencies via pre/post hooks"""
        # Seeds are root nodes in the DAG. They cannot depend on other nodes.
        # However, it's possible to define pre- and post-hooks on seeds, and for those
        # hooks to include {{ ref(...) }}. This worked in previous versions, but it
        # was never officially documented or supported behavior. Let's raise an explicit error,
        # which will surface during parsing if the user has written code such that we attempt
        # to capture & record a ref/source/metric call on the SeedNode.
        # For more details: https://github.com/dbt-labs/dbt-core/issues/6806
        hooks = [f'- pre_hook: "{hook.sql}"' for hook in self.config.pre_hook] + [
            f'- post_hook: "{hook.sql}"' for hook in self.config.post_hook
        ]
        hook_list = "\n".join(hooks)
        message = f"""
Seeds cannot depend on other nodes. dbt detected a seed with a pre- or post-hook
that calls 'ref', 'source', or 'metric', either directly or indirectly via other macros.

Error raised for '{self.unique_id}', which has these hooks defined: \n{hook_list}
        """
        raise ParsingError(message)
Disallow seeds to take implicit upstream dependencies via pre/post hooks
core/dbt/contracts/graph/nodes.py