Question

Why did Elie Wiesel giving a speech a buchenwald concentration camp?

Answer 1

Elie Wiesel gave his speech because it was a reason for him to come and visit his father's grave even though his father didn't have a grave. 
 
hope this helps

Answer 2

He had gave his speech  because so he had a reason to go and visit his fathers grave even though his father wasn't given a grave