What was the age of ibn Abbas (May Allah have mercy on have) at the time of Prophet Muhammad's (SAW) death?

Question

I'm confused whether the age of Ibn Abbas (May Allah be pleased on him) was 8 or 13 at time of the death of Muhammad (SAW).

I've read a book which says, it is 8. But in different websites, it says, 13. In Wikipedia, they have failed to provide any references to support "13". However, even if they give, I don't care. Their references are not always reliable.

In other website, they have also failed to provide references to support "13".

So plz answer with references from the books of the reliable and renowned scholars so that they can be cited as reference or from such type website for example: Islamqa. I mean, I want a reliable references. Not from any website. That's why, I would be thankful if anyone give references from the books of scholars.

Answer 1

There are at least six reports on the age of Abdullah ibn Abbas at that time of the death of the Prophet Muhammad ﷺ: ten, twelve, thirteen, fourteen, fifteen or sixteen years. See فتح الباري - فضائل القرآن , باب تعليم الصبيان القرآن .

Among the references for thirteen and fifteen years include:

ابن عباس يقول: ولدت قبل الهجرة ونحن في الشعب فتوفي النبي صلى الله عليه وسلم وأنا ابن ثلاث عشرة

^{— Mustadrak al-Hakim}

ابن عباس رضي الله عنهما قال: توفي رسول الله صلى الله عليه وسلم وأنا ابن خمس عشرة وقد ختنت

^{— Mustadrak al-Hakim}