Behold, I know your thoughts, and the devices (or, surmisings) which ye wrongfully imagine against me. I know, i.e.' what you think of me. I am quite aware that you regard me as having brought my afflictions upon myself by wicked deeds, which I have succeeded in keeping secret.
You have not openly stated your surmises. but it has been easy for me to "read between the lines," and understand the true meaning of your insinuations, which are all wrongful and unjust.