American ISIS hostage's family get unlikely ally

An urgent plea to the Islamic State of Iraq and Syria (ISIS) is getting some unusual support.

The mother of hostage Peter Kassig sent a tweet to the terror group, asking how to save her son after a top al Qaeda official backed her cause, reports CBS News correspondent Margaret Brennan.

Three weeks after ISIS threatened to execute Abdul Rahman Kassig, a senior fighter from the Nusra Front, Abu Omar Aqidi, allegedly took to Twitter to express his opinion on the matter.

The Nusra Front, a Syrian jihadi group aligned with al Qaeda, has been at odds with ISIS, which al Qaeda leaders have said is too brutal.

In Aqidi's tweets, he claims Kassig gave him medical help last year in the same part of Eastern Syria where Kassig was providing emergency aid before he was taken hostage.

That post got the attention of Kassig's parents and reinvigorated their online campaign featuring testimonies from aid workers.

Kassig's colleague named Marwan shared a story of how he witnessed Kassig provide aid to Syrian refugees at a medical center in Tripoli, Lebanon. He called on ISIS to release him.

But it's Aqidi's tweet that got the jihadi community's attention, creating debate about whether it's moral to execute someone who had helped them.

Whether this is about saving a life or simply competition between jihadis is unclear.

"I don't know how much pull that really has, but I'm quite sure this is a 3D game of chess and Nusra understands how to play the game, as does ISIS," said terror analyst Phillip Smyth.

But Kassig's mother Paula wants the world to know that her son is more than just a hostage.

"He's compassionate, he is smart, he has love for all who need help," she said.