Question Summary:
What is the definitive age of accountability?

Question Detail:

What is the definitive age of accountability
I've always thought that it was at puberty. So I decided to do some research on the subject and encountered something interesting. What I encountered is Al-Quran 46:15-16. So are these the only and closest ayats in the quran that associates age with being held accountable? If so, does this mean that this refers to the age of accountability? I came across this at this website - http://www.submission.org/Diana.html  = I urgently want to know if what this muslim is saying is the truth or not.

This is an extremely important basic question and fact of life! Please help me resolve this question once and for all! I've run across many websites that say it's puberty, but do not source the quran or hadith reference. I am looking for authentic hadith or quran to specifically state how old a person is before they are held accountable. For example, is it possible to be 19 years old and be cursed to Hell for sin or not? Thanks so much in advance.

Here's the only hadith I could find - Abu Dawud

Book 38, Number 4387:

Narrated Ali ibn AbuTalib:

Ibn Abbas said: A lunatic woman passed by Ali ibn AbuTalib. He then mentioned the rest of the tradition to the same effect as Uthman mentioned. This version has: Do you not remember that the Apostle of Allah (peace_be_upon_him) has said: There are three whose actions are not recorded: a lunatic whose mind is deranged till he is restored to consciousness, a sleeper till he awakes, and a boy till he reaches puberty?

Answer :

In the name of Allah, Most Gracious, Most Merciful
Assalaamu `alaykum waRahmatullahi Wabarakatoh
There are two ways of determining buloogh (maturity/puberty).  
A) Physical maturity
B) Maturity by age
According to Shariah, if a boy experiences Ihtilaam (wet dream) or has the ability to impregnate he will be regarded to be Baligh (mature). This is referred to as physical maturity. However, if a boy does not become physically mature by the age of 15, Shariah will consider him to Baligh from the age of 15.
A girl will be regarded to be Baligh (reach the age of puberty) if she experiences Haidh (menses) or she becomes pregnant. If she does not experience menses by the age of 15, she will be regarded to be Baligh and all the Laws of Shariah will apply to her. (Shaami Vol.6 Page 580 H M Saeed)
The above ruling of 15 years has been deduced by the Hadith of Abdullah bin Umar (Radiallahu Anhu). On the occasion of Uhud he presented himself to Rasulullah (صلى الله عليه وسلم) to participate in the expedition while he was 14 years. Rasulullah (صلى الله عليه وسلم) did not allow him as he was too small. The following year in another expedition he presented himself and Rasulullah (صلى الله عليه وسلم) accepted him to participate.
The Fuqahaa deduce from the above quotation that the age for maturity is 15 for girls and boys. (Shaami Vol.6 Page 581 H M Saeed)
And Allah knows best
Wassalam
Muhammed Zakariyya Desai,
Checked and Approved by:
Mufti Ebrahim Desai
Darul Iftaa, Madrassah In'aamiyyah