Ruppin may have travelled to Germany in 1934. Hajj Amin spent the war there and took blood money from the Nazis to spew antisemitic propaganda and recruit Muslims to the Nazi cause.
Perhaps you should read Hajj Amin’s diary from Nov 28, 1941:
“Our fundamental condition for cooperating with Germany was a free hand to eradicate every last Jew from Palestine and the Arab world. I asked H!tler for an explicit undertaking to allow us to solve the Jewish people in a manner befitting our national and racial aspirations and according to the scientific methods innovated by Germany in the handling of its Jews. The answer I got was: “The Jews are yours.” 4/4