A Qur’anic passage may present an event briefly, while another presents further detail. Comparing the passages allows one portion of revelation to clarify another; this is tafsīr al-Qurʾān bi-l-Qurʾān.
The story of Adam in al-Baqarah and references to divine knowledge can be read together. Likewise, a relatively condensed statement concerning Jesus in Maryam may be studied alongside the expanded discussion of his mission in Āl ʿImrān.
Caution: comparing passages is a valid method, but explanatory reconstructions must never be represented as additional words of the Qur’anic text.