Torah as the source of all blessing

שתי הלחם רומז למ"ש גדולה תורה שנותנת חיים לעושיה בעוה"ז ולעוה"ב.

The shtei halechem (the two loaves brought on Shavuos) alludes to what is said: "Great is the Torah, for it gives life to those who do it, in this world and in the World to Come."

The two loaves of Shavuos hint to the power of Torah, which sustains a person both in olam hazeh (this world) and in olam haba (the World to Come).

לחם מן השמים ומן הארץ הכל תלוי בתורה דכתיב לקח טוב נתתי לכם במד' יש לך מקח יש בו כסף כו' והתורה יש בה כסף זהב שדות וכרמים כי הכל נברא בתורה מכש"כ שקיום הכל על ידי התורה.

Bread from heaven and bread from the earth — everything depends on the Torah, as it is written, "A good acquisition (lekach tov) I have given you." The Midrash says: there is a purchase that contains silver, and the Torah contains silver, gold, fields, and vineyards. For everything was created through the Torah — all the more so that the existence of everything is sustained through the Torah.

All sustenance, whether spiritual ("from heaven") or physical ("from the earth"), flows through Torah. Since the world was created by means of the Torah, it is certainly Torah that keeps everything in existence.

וכתיב ה' עוז לעמו כו' ה' יברך את עמו בשלום.

And it is written: "Hashem will give strength to His people, Hashem will bless His people with peace" (Tehillim 29:11).

The "strength" Hashem gives His people is the Torah, and through it comes blessing and shalom.

וכמו דאיתא בשבת דלא אשתכח בי' מנא ומ"מ כתיב ויברך דכל ברכאין בי' תליין.

And just as it is taught regarding Shabbos, that no manna was found on it, yet nevertheless it is written, "And He blessed [the seventh day]" — for all blessings are suspended from it.

Although no manna fell on Shabbos, the Torah still says Hashem "blessed" it, because Shabbos is the source from which all the week's blessings draw down.

לכן לחם הפנים נערך בשבת.

Therefore the lechem hapanim (showbread) was arranged on Shabbos.

Because Shabbos is the wellspring of blessing for the whole week, the showbread in the Bais Hamikdash was set out specifically on Shabbos.

כמו כן בשבועות יום שניתנה בו תורה כולהו ברכאין בי' תליין לכן שתי הלחם בעצרת.

So too on Shavuos, the day on which the Torah was given, all blessings are suspended from it — therefore the two loaves are brought on Atzeres (Shavuos).

Shavuos, the day of mattan Torah, is itself a source of all blessing, so the loaves of blessing are brought specifically then.

ושתי הלחם הוא עוד למעלה שהם שורש הי"ב לחם שבלחם הפנים:

And the two loaves are on an even higher level, for they are the root of the twelve loaves of the showbread.

The two Shavuos loaves stand above even the twelve showbreads — they are the root and source from which those twelve draw, just as Torah is the root of all sustenance.

Summary: The two loaves of Shavuos express that the Torah is the source of all life and blessing — physical and spiritual alike. Just as Shabbos and the showbread channel the week's blessing, Shavuos, the day the Torah was given, is the root from which all blessing flows into the world.