see the translated words of Shekau earlier video:
To the infidels of Nigeria, president Muhammadu Buhari and his associates, Idris Derby, the man goat sighted man. To the citizens of Niger Republic and the entire people of Africa and the world in general.
You must listen, I am fine and alive but you must know if my day comes you will not have seen me,many dead people did not plan their death but they died. Many again are alive despite plot to kill them on the surface of the earth.
There is nothing that was not plotted against our revered Prophet Mohammed but he succeeded against all the plots. You should do all you can with your Benjamin Netanyahu, you should continue plot with your Banki-Moon, do all your plot with your Geneva people, all your plans according to Allah are not up to a cob-web.
This is what we are here for, doing allah’s work and working hard to spread to the entire world. We are not working for the world or working with our wisdom; we are working for Allah. We are not sociologists; what we are practicing is ‘Quranism’.
We are Hadith followers. We are not learned but knowledgeable according to Allah’s injunctions. We are not wise but Allah’s followers that is why we are above your bragging and human power.
Stop all this your bragging to us, that you have planes, that you were in Iraq and killed mujahideens. You are just flying on the sky which Allah possess, is it with this that you will kill us?
also check what he said to buhari in a video here..watch video here
