133. " nay, were you witnesses when death approached jacob ?
when he said to his sons:
` what will you worship after me ? ' they said:
` we will worship your god and the god of your forefathers abraham,
ismail and isaac, the one (true) god (alone) and to him we do submit '."
134. " that is a nation that has passed away;
theirs is that which they have earned, and yours is what you have earned;
you shall not be questioned for what they had been doing."

occasion of revelation

a group of the jews believed that when jacob (a.s) was on his
deathbed, he enjoined on his children the same religion which the jews
currently believe in (with all its corruption of the scriptures). for the
nullification of their belief, allah sent down this verse. 1

commentary :
everyone is responsible for his own deeds

as it is also understood from the apparent meaning of the verse,
there were some rejectors of islam who falsely charged jacob (a.s.), the
prophet of allah, regarding this matter. (the matter was mentioned
in the description of the occasion of revelation.)

to reject this false claim, the qur'an says:

" nay, were you witnesses when death approached jacob ?...":

were you there when he frankly questioned his children the way he did?

yes, that which you (jews) charge jacob (a.s.) with is not true.
the factual account which occurred was that:

"...when he said to his sons:` what will you worship after me ? '.."
"...they said: ` we will worship your god and the god of your forefathers
abraham, ismail and isaac, the one (true) god (alone)
and to him we do submit'."

yes, he did not enjoined them with anything but to believe in
monotheism and to submit to the command of allah, which is the root
of submission to all the divine ordinaces.

it can be deduced from this verse that verse that when jacob was on his
deathbed, a feeling of anxiety and worry existed in him about the future
of his children. finally he expressed his anxiety and asked his sons what
they would worship after him. he especially asked ` what (thing) ' and
he did not ask ` whom ', because there were some idol-worshippers in
the locale who used to prostrate before some particular ` things '. jacob
wanted to know whether there was any tendency towards those beliefs
in the depths of their hearts. but when he heard his children's answer,
he found, again, his peace of mind.

this is also noteworthy that ismail (a.s.) was not jacob's father or
forefather, but he was jacob's uncle, whereas in the verse under
discussion, the term / 'aba' / which is the plural of the word / 'ab /
(father) has been applied. this makes it clear that, in the arabic
language, this word was sometimes used for ` uncle '. hence, we say
that if this word has been used regarding 'azar in the qur'an, it does
not negate the fact that 'azar was abraham's uncle, not his father.

* * * *

 the last of the above verses mentioned is an answer to one of the
delusions of the jews. they emphasized very much on their ancestors
and the honour and glory they ascribed themselves in relation to
allah. they imagined that even when they tainted themselves with sin,
they could be rescued under the comforting shade of such ancestors.
then, the qur'an says:

" that is a nation that has passed away;
theirs is that which they have earned,and yours is what you have earned;..."

and, in the same way that they are not responsible for your deeds,
also,

"... you shall not be questioned for what they had been doing."

therefore, instead of expending all your energy trying to prove
that you, by right of ancestry, deserve the honour and high position that
your pure ancestors enjoyed, you should try to improve your own faith
and deeds.

the addressees in this verse are apparently the jews and ` the
people of the book ', but it is evident that this statement is not
specifically referring to them alone, in that this basic principle, pertains
to us muslims, too. 

1 tafsir-i-abulfutuh-razi,vol. 1, p.339