Why did Portia have to follow her fathers will?

Question

In The Merchant of Venice why did Portia have to follow her fathers will.
Was it out of respect or was it an actual law to have to follow some ones will instructions?
Thanks

Answer 1

I'm pretty sure she had to follow the will.

www.sparknotes.com or something like it might help.

p.s. we named our dog portia after this character =]

Answer 2

It was out of respect for the wishes of the dead founded on tradition. Other brides in similar situations also observed similar mores, sense of morality, decency, and modesty. Age and wisdom were valued at the time.

Nerissa provides the correct:

NERISSA: Your father was ever virtuous; and holy men at their death have good inspirations: therefore the lottery,
that he hath devised in these three chests of gold,
silver and lead, whereof who chooses his meaning
chooses you, will, no doubt, never be chosen by any
rightly but one who shall rightly love. But what
warmth is there in your affection towards any of
these princely suitors that are already come?