大般涅槃經義記 6.14

6.14

又問者，爾六通之中亦應如是但知過現，何用天眼知未來乎？釋言：不類。六通知事，三世事別，故須別知；此觀空理，理同可推，故不別論。

Another question asks: If so, should one within the six superknowledges also only know the past and present, so what use is the divine eye to know the future? Explanation: They are not analogous. The six superknowledges know phenomenal affairs, and affairs of the three times differ, so they must be known distinctly; this contemplation is of the principle of emptiness, and since the principle is identical, it can be inferred, so it is not treated distinctly.