I am familiar with the usual usage of "look to sb to do sth" but in the following sentences, the meaning does not make sense to me:
'I will no longer be a suppliant for knowledge which the gods withhold. Let them look to it that they do me no wrong. I will do my duty as best I can and if I err upon their own heads be it!'
It sounds weird to me because those (gods) referred to are also the object of the phrase (that they do me no wrong..). A small side-question, the last sentence, does it mean the following: "if I err, in their eyes/in their view, then so be it!"