I want to translate the following sentence.
Those sly bad men took the money out of the pockets of the courageous young man.
I came up with the following Esperanto sentence.
Tiuj ruzaj malbonaj viroj forprenis la monon el la poŝojn de la kuraĝa juna viro.
Should I use poŝoj or poŝojn?
el la poŝoj is correct.
The accusative can be used with a preposition to show direction. For example mi iris en la domon means that the person travelled towards the interior of the house. This is distinct from mi iris en la domo which could mean that the person moved around in the inside of the house, although that would be quite a strange way of phrasing it.
However, the preposition el is special in that it already indicates direction all by itself. Mi iris el la domo already unambiguously means that the person travelled from the inside of the house to the outside. Therefore adding the accusative after el doesn’t add any extra meaning and it would be considered a mistake. The same thing applies to al, ĝis and de.
See this page of PMEG for more information, and in particular this quote:
Kelkaj rolvortetoj per si mem montras direkton: al, ĝis, el kaj de. Tiuj rolvortetoj neniam montras pozicion. Post ili oni ne uzu N-finaĵon: al la urbo, ĝis la fino, el la lernejo, de la komenco, disde la patrino, ekde Februaro, de post la somero, for de Tokio (ne *al min*, kio signifus *al al mi*).
