Secret Deeds and the Sun's Departure
Interpreters believe that one who performs secret deeds, whether good or bad, and sees the sun's departure or its rise after setting, may indicate the concealment or revelation of their affairs. The sun's rise after setting may also signify the return of a divorced wife, a pregnant woman's delivery, thriving livelihood, or victory in jihad and war. For the ill person, it may indicate death.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam