Taken from: islamicbook.ws المعتمد في أصول الفقه

(Note: the book first treats the fact that it is allowed (or not) of speaking in an unknown language. The exemple often used is an Arab talking to a Zinj. İt has little importance for us.)

If it were possible for a speaker not to intend his speech to be understood, then it would be possible for a black person to address an Arab in his language (bi-zinjiya), even though the Arab did not speak this language inasmuch as it is unnecessary to make the addressee understand; for the Arab has no apparent meaning (to attach to) the language of Blacks. 

And God, glory be to Him, wants something else but does not explain to us that it is permissible ………………  nor does it explain to us that and in that it is equated with the speech of the Zinj because I do not understand anything about it at all …………………..

Speech useful for repetition ……………………. then is it permissible to address from the Arab to the Zinj, and it is said to him; I know that we wanted something by this speech …………………….

………….. the forgiving person thinks that he wanted something in his speech, then they told him that he should address him to the Zinj and not say that I wanted something………

……………….. it would have been better to address in Arabic the Zinj and you do not explain to him immediately, ………………… and if you say that he did not address him properly in Zinj (language) because the Arabs do not know anything about what the Zinj speak ………….. Either you regard knowledge in good speech as the perfection of what is meant, or you regard knowledge as some of what you consider.  First, you are obligated not to delay the statement, because it is not possible, with his loss, to know the perfection of the meaning, even if you explain it; The second requires you to have a good address of the Arabic with the Zinj, because if the Arabic knows his rule, the Zinj who is addressed to him knows that; In his speech, he wanted something, either the order or the prohibition, or something else; The listener is able to know by him what the speech has benefited him …………….

  ……….. and as for the Arabic, he was not able to know what the Zinj speech was for, so he did not know that speech is either an order, a forbidding, or a news or intelligence, Arabs are not able to find out what was said in the words of Zinj ……..

Speech for the Zinj to address the Arab with. The Arab’s belief is that it is not good for that, because just as it is permissible to have in the words of the Zinj, it is permissible to disagree with it, so he does not believe in that speech will benefit him  ……………..

God speaks to us with something that we do not understand, such as the discourse of the Zinj and it is necessary to know ……………. the point of what is meant in the speech, so it is permissible for the Arab to speak to the Zinj because it indicates determination and belief if the speaker is a master of the listener ……………..

………….. the course of the Arabic speech would have flowed into the Zinj the difference between them is that an Arab does not understand a Zinj he would not be able to understand it if he did not interpret it to him…….. It is not like the one who engaged in public, and it is permissible to have the provision in the Sharia and what they said, they are obligated to do ……………………..