In your thesis, specifically in the discussion section, you will have to present an argument, or a set of arguments, about the significance of your results, any limitations or problems of your research design or implementation, and consequent proposals for future work. This requires you to interpret your results and locate them in the context of existing research.
This usually occurs in the discussion section of a thesis based on empirical research and generally includes the following. This is not a fixed order and you won’t necessarily include all these elements.
(from Hopkins and Dudley-Evans, 1988).
There are therefore two reasons for referring to the research literature in the discussion of results. First, you need to compare your results with those reported previously. This allows you to show how your findings reflect, contradict or extend previous research. Second, when you are generalising from your findings, you can use the existing literature to support your deductions or hypotheses.