Some verses of the Geneva Bible have marks, which look like quotation marks. Are these marks part of the text or were they added later?
For examples see 1 Samuel 28:17 between mine and hand, 1 Samuel 29:1 between pitched and my, and 1 Samuel 29:2 between the and princes.
You have good eyes. It took a while to find the marking that you were referring to. Let me make a few points that may help.
First, these notations are not part of the original text of the Hebrew Bible or the Septuagint (LXX).
Second, these notations are original to the Geneva study bible. If you look closely, these quotation marks correspond to the marginal notes. Often times text have a little apparatus that gives you extra information. So, in chapter 29:2, before the word, "princes" there is what looks like a quotation mark. On the left margin you will see that same mark and it will say "captains." From this you can clearly see that it is a scholarly mark that is giving you an alternate reading.
In short, the marking is not original to the Hebrew or Greek text, but it is original to the Geneva study bible.
Wow, I'm a total ditz. I should have figured that out myself. You have the honor of being the first to answer one of my questions.