Imam Sadiq (AS) has said:

 "Surely the Quran is not to be read in a rush or very quickly, rather, it should be recited in slow, measured portions; and whenever you reach an ayah (verse) which talks about Heaven, then stop (at that verse) and ask from Allah (SWT) (the bounties of) Heaven, and whenever you reach an ayah which speaks about the Hell, then stop (at that verse) and seek protection from Allah from the Hell-fire (and the punishment)."

 Usool-e-Kaafi

Vol 3, Page 301