[Avodah] Vayeitze "Watch Whom You Marry"

[SBA]

R' Richard Wolpoe asked:
> How did HKBH let Y'aaov Avinu have relations with Le'ah that
> night when his Kesubbah said Rachel - which meant his bi'ah
> was assur.

The Chizkuni writes (29:25): "Ve'im Tomar, Veha hayu lehu kidushei Taus dehu
savur shehu Rochel?
Veyesh Lomar, misheyoda shehu Leah bo'al leshem Kidushin.."

(However, lechoreh from the pasuk it is mashma that Yaakov only realized
that it was Leah in the morning.?)

And while on the Chizkuni, he also talks about the problem of Yaakov
marrying 2 sisters (29:28). After all, as we know, Yaakov Avinu observed the
entire Torah ("VeTaryag mitzvos shomarti")?

If I understand what he writes (and I am not 100% certain that I do), he
says that 'ger shenisgayer kekatan shenolad dami' - suggesting that Rochel
and Leah were nisgayer. 
Secondly that Rochel and Leah had different - non-Jewish - mothers and with
goyim the offspring reckoned according to their mother - thus they were not
real sisters.

SBA