Languages with subordinate imperatives?

Question

English does not allow an imperative to be used in a subordinate clause:

1. Eat that pizza!
2. *There's a pizza on the table, which eat! (="which I order you to eat")
3. *I told you eat that pizza!

(A superficially similar variant of 3 is grammatical: "I told you, eat that pizza!" - but here the imperative clause is not subordinate.)

But there's no obvious reason why this should be so. Pragmatically, an imperative is usually paraphrasable by a declarative, e.g. "I order you to Verb" or "You must Verb", and such declaratives are subordinatable like any others. Indeed, Ancient Greek allows subordinate imperatives to a limited extent (examples from Smyth's Greek Grammar, p. 411):

1. kratêrés eisin ... hôn krât' érepson "There are mixing bowls ... the rims of which fill!" (="the rims of which you must fill")
2. oîsth' hò drâson? "Do you know what do (impv.)?" (="Do you know what you are to do / what I'm telling you to do?")

So: which other languages allow subordinate imperatives? (By "imperative" here I mean a morphological form whose main or sole function is to express a directive speech act. There are languages where "subjunctive" forms of various kinds can be used to express commands in both main and subordinate clauses, but I'm not asking about those.) Are subordinate imperatives cross-linguistically rare, or do they only happen to be rare in modern European languages? And if they are rare, why should this be? (Presumably the answer should have to do with the differing pragmatic status of the content of main and subordinate clauses: e.g. in declarative sentences, the content of a subordinate clause often cannot be directly affirmed or denied, which seems relevant somehow.)

Answer 1

In Russian, it is possible to use imperatives in different kinds of clauses, including attributive clauses (like your English example 2). Both of your Greek examples can well be translated into Russian with imperatives in the same positions as in Greek. The Russian language lacking Subjunctive and Optative moods, its imperative can be used in their meaning, such cases I will exclude from my answer, although Russian is brimming with them. I will give examples with the imperatives used only as direct commands.

In the following examples imperatives will be italicized.

First, my translations of your examples.

English example 2:

*There's a pizza on the table, which eat! (="which I order you to eat")

Лежит там пицца на столе, которую ты поедай немедля.

Greek 1:

There are mixing bowls ... the rims of which fill!

Посуда там стоит, которую ты до краёв наполни.

Greek 2:

Do you know what do?

Ты знаешь, что сделай?

And there are some examples from the Russian National Corpus:

1. Выложите лакомство в фруктовую вазу, края которой украсьте так, как вам подскажет фантазия. - "*Put out the delicacies on a dish, the rims of which decorate the way your fantasy suggests."

2. Возвратись теперь в своё владение, в котором ожидай меня (...). - "*Now go back to your domain, in which wait for me."

3. Все действия могут проходить по определенным принципам и правилам, которых придерживайтесь в реальном бою. - "*All the actions can take place according to certain principles and rules, which keep in a real combat."

From a letter by Anton Chekhov:

Привези мою фуражку маленькую, которую возьми у Ольги. - "*Bring me my small cap, which take from Olga."