I am unaware of any animal that is as cruel as Israelis— not even crocodiles. They bomb schools, hospitals, refugee camps, orphanages, UN feeding stations, water works, power plants, ambulances, kids playing on the beach. They put millions of people in a siege. They shoot children going to school. They kidnap kids and harvest their organs. They inject prisoners with disease pathogens before releasing them. They murder by land, sea and air and worst of all, they slander their defenseless victims as ‘terrorists’.
An anonymous person wrote a comment on July 21, 2014 on PressTV.ir that uses David Attenborough name. That comment was strongly upvoted and people made Facebook memes out of it.
Given that social media activity the Arab News took it as fact for their article on August 8, 2014.
The blog Toxic Drums analyses the case in more detail.
Anyone could have written that comment and there's no reason to believe that it was David Attenborough. If David Attenborough wanted to say something on the issue the 88 year old would likely write an OPed in a newspaper instead of commenting on an Iranian news website.