Validity ensures that a research is well structured and its provide a result that can be generalized with the population that is concerned.
Internal validity is used to establish relationship between two variables and also ensure that valid inference can be drawn. This is done when a researcher can state that the changes observed in the study or dependent variable were due to the manipulation of the independent variable and not due to another factor which means no other variable contributes to the effects.
The advice of Bise helped king PN Shah to successfully gather / collect adequate money for purchasing weapons for the unification-centric wars. It clearly shows that Bise was a non-paid advisor to the king PN Shah.