The words "gone astray" is an idiom that means "to be unfaithful." Alternate translation: "if you have not been unfaithful to your husband" (See: [[rc://en/ta/man/translate/figs-idiom]])
The phrase to "be free" from something means to not be harmed by it. Alternate translation: "this bitter water will not harm you, though it is able to" (See: [[rc://en/ta/man/translate/figs-idiom]])
Here the bitter water is described as being able to bring a curse. This means that when the woman drinks the water it cause her to be unable to bear children, if she is guilty. Alternate translation: "this bitter water can be a curse to you" (See: [[rc://en/ta/man/translate/figs-personification]])