I want to know the meaning of the Hadeeth where the Prophet, sallallaahu 'alayhi wa sallam, forbade boys from going out during the first part of the night because devils are around at this time. Can they go out after sunset?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

Imaam An-Nawawi explained the meaning of this narration. He stated that Muslims have to prevent their boys from going out at this time, because this is the time when devils spread around. He added that the narration stated the permissibility of letting them out one hour after night fall. This, in turn, specifies the period when boys should be confined in their homes: which is the first hour of the night, and not the whole night. Therefore, once this time has passed, it is permissible to let the boys out for playing or otherwise.

Ibn Al-Jawzi mentioned the wisdom behind limiting this rule to boys only. He stated that boys are feared for at this hour because they usually do not cleanse after urinating and they are sought by the devils for this impurity, and boys usually do not say the legislated mention of Allaah that guards them against devils. Hence, the devils attach themselves to whatever they can find when spreading, this is why it is feared for boys to go out at this time.  

Allaah Knows best.