Active prohibition forbids the addressee from performing an act; passive prohibition forbids an act being done to a person or thing:
AddresseeActivePassive
m. singularلَا تَرْمِلَا تُرْمَ
dualلَا تَرْمِيَالَا تُرْمَيَا
m. pluralلَا تَرْمُوالَا تُرْمَوْا
f. singularلَا تَرْمِيلَا تُرْمَيْ
لَا تَرْمِ: do not throw. لَا تُرْمَ: do not be thrown. The passive reading follows from the vowel pattern of تُرْمَ, not simply from the presence of lā.