The imperative lām takes a jussive imperfect and can express a command or injunction for non-addressee persons as well:
PersonActive jussive commandPassive jussive command
heلِيَرْمِلِيُرْمَ
they twoلِيَرْمِيَالِيُرْمَيَا
they menلِيَرْمُوالِيُرْمَوْا
sheلِتَرْمِلِتُرْمَ
Iلِأَرْمِلِأُرْمَ
weلِنَرْمِلِنُرْمَ
لِيَرْمِ: let him throw. لِيُرْمَ: let it be thrown. The passive has a different grammatical focus: the affected entity, not the performer.