4 ideas
Croesus of Lydia asked Delphi whether he should march against Persia and was told that if he crossed the Halys River he would destroy a great empire. He heard what he wanted, did not ask which empire was meant, attacked Cyrus, and lost Lydia; the empire destroyed was his own. When he complained, the oracle answered that the fault was his for not asking a second question.
A prediction worded so that more than one outcome fulfills it cannot be falsified, so whoever issues it keeps their authority however events turn out. All of the risk shifts to the person acting on it. The remedy is to ask the follow-up question that forces the forecast to name which outcome it means.
Herodotus writes down what priests, merchants and soldiers told him and says which source each account came from. He then states openly whether he believes it, sometimes giving competing versions side by side and leaving the reader to judge. Keeping the record apart from the verdict lets later readers re-weigh evidence the author himself rejected.
To explain Egypt, Herodotus starts with the Nile's yearly flood and the silt it leaves. For the Scythians he starts with the treeless steppe that let them live as nomads no invader could pin down. He treats a people's customs, and the stories they tell about themselves, as outgrowths of the land they live on.