Even if it were in heaven or over the sea we would still be duty-bound to strive for it, but it’s not as distant as all that. It is accessible wherever we happen to be.
There must be a symbolism in the use of the words “in heaven” and “across the sea”. Possibly it is this: The Torah is neither spiritually and intellectually beyond us, nor is it geographically inaccessible.
Take each category on its own. The first says that the Torah is not too high for us – “in heaven”, as it were. God bless you if you’re a saint or a genius, but most people aren’t. Saints and geniuses can find their way to the Torah; so can the rest of us. On one level or another, we can all comprehend and adopt Torah ideas and insights.
The second category says that the Torah is not “across the sea”. If you live in the Diaspora, forget about saying, “Things are different in Israel. There it is easier to follow the commandments”. Israel is certainly different and superior, but don’t make it an excuse for not raising your religious levels in whichever place you happen to be.
And if you do have the blessing of being in Israel, don’t make an excuse out of that either, saying, “If I were in Jerusalem things would be different”. In Jerusalem things would be different, but that shouldn’t stop you elevating yourself anywhere else.