A senior al Qaeda jihadist is begging ISIS to spare the life of American hostage Peter Kassig, saying Kassig served as an aid worker in Syria and treated jihadi fighters — including himself.

Kassig, 26, is the next Western prisoner slated for execution.

Abu Omar Aqidi, a leader of Jabhat al-Nusra, a Syrian group linked to al Qaeda, tweeted his support for Kassig.

Kassig removed shrapnel from his wound and helped treat other jihadists in Syria, so he does not deserve to die, Aqidi wrote.