Voice changes the orientation of the event; passive does not mean negative or past.
RootActive pastPassive pastActive presentPassive present
ق و لقَالَقِيلَيَقُولُيُقَالُ
ب ي عبَاعَبِيعَيَبِيعُيُبَاعُ
ر م يرَمَىرُمِيَيَرْمِييُرْمَى
د ع ودَعَادُعِيَيَدْعُويُدْعَى
بَاعَ التَّاجِرُ الْكِتَابَ
Translation: The merchant sold the book.
بِيعَ الْكِتَابُ
Translation: The book was sold.
The object of the first active sentence functions as the passive subject in the second.