[Avodah] Rosh Hashana: The Universal Two Day Yom Tov

[Prof. Levine]

At 07:13 PM 9/12/2013, Micha Berger wrote:
>Besides, a reason why Yom Tov sheini shel goliyos has value is because
>it takes us two days in galus to achieve the same qedushah one can reach
>in one day in Eretz Yisrael!

>And this isn't just a nice vort.... It is invoked lehalakhah in favor of
>keeping one day when in EY (or one plus the 2nd day lechumerah) because
>being "machmir" and keeping two is actually insulting qedushas ha'aretz.

Sources,  please.