Ki tavo'u lei'ra'os panay, mi bikesh zos m'yedchem r'mos chatzeiray?
Yishyahau haNavi, in the haftarah of Shabbos Chazon, says to those people coming to the Beis haMikdash, "Who needs you here? What business do you have trampling through the Mikdash?" When you come to make aliya la'regel on the three regalim, it's all for naught.
That's the gist of what the pasuk means, but that first phase is difficult. If the pasuk means to speak about coming to see Hashem in the Mikdash, it should say "liros panay." If it means to speak about being seen by Hashem, it should say "lei'ra'os lifanay." What's "leira'os panay?" It's like a grammatical hodge-podge that makes no sense.
You can ask the same question about the pasuk in chumash that talks about aliya la'regel. "...Yera'eh kol zechurcha es pnei Hashem" Here too, if it means to see Hashem, it should say "liros;" if it means to be seen, it should say "lifnei Hashem?"
There is an amazing Alshich that you can find in the Maros haTzov'os on Shmuel I 2:11 that I will save you some trouble looking for -- in your standard edition with the Malbim it's printed on the bottom of the page all the way in perek 22. You don't make aliya la'regel "liros," to see G-d, because that's impossible -- G-d has no face. The reason to make aliya la'regel is to be seen. But, says the Alshich, it's not "lifanei," but rather "es panay." There is a Zohar that tells us that the faces of tzadikim are called "apei Shechinta," the face of the Shechina. You want to see G-d's face? Look in the mirror. G-d wants us to be tzadikim -- he wants us to be able to look in the mirror and see his face, his reflection there.
On a previous 9 Av I posted a pshat that the greatness of Moshe Rabeinu, "temunas Hashem yabit," is not that he looked up to the Heavens and saw G-d like no other navi, but rather that when Moseh Rabeinu saw a simple Jew in Klal Yisrael, that was for him "temunas Hashem yabit." Moshe Rabeinu saw the pnei Hashem in every Jew he met. That's a navi, a manhig, the greatest of great (see the Netziv on that phrase).
The word "es" in Tanach often means the same as "im," with. The mitzvah of aliya la'regel is "yera'eh kol zechurcha" -- to be seen, but in order to stand before Hashem and be seen, you have to come "es panay" = im panay, with MY face, with Hashem's face reflected in our own. You want to have a Beis haMikdash and be able to walk in its halls? First ask yourself when you walk down the street do people say there goes the pnei Hashem, there goes a reflection of kvod Shamayim.
This is what Yishayahu was telling Klal Yisrael. We were given a mitzvah "leira'os panay" -- to come to the Mikdrash so that our faces, our "apei Shechinta," can be seen by Hashem. But if we don't behave the way we are supposed to, if our faces are indistinguishable G-d forbid, from the faces of the nations around us, then "Mi bikesh zos m'yedchem r'mos chatzeiray?"
My daughter this afternoon sent the picture below from Yerushalayim Ir Ha'kodesh where she has the zechus of spending the summer:
There were mobs of people by the kosel, by the makom mikdash.
I got this picture a short while after getting home from finishing kinos, which closed with the kinah of the Bobover Rebbe written for the Holocaust.
Do you think any Jew who lived through the horrors of the war would have imagined that just 70 years later we would have hundreds of Jewish youth gathered on 9 Av in our Jewish homeland, standing by the kosel under a Jewish degel, protected by Jewish soldiers, so that they could learn Torah and sing ani ma'amin in that makom kadosh?
We live in times of such great opportunity, such great potential, but when you read the news that is always so filled with machlokes and tragedy it is easy to lose sight of what we have achieved (or maybe I should say what Hashem has given us) and where we are headed. Of course we are still in galus, and it's still 9 Av, and we have what to mourn, but we also need to recognize chasdei Hashem. One day I am sure that we will not just be standing outside the walls of the kosel, but on top of the mountain as well. That's probably as unbelievable to most people today as dream of standing by the kosel would have been to someone 70 years ago. Yet here we are. But the navi is clear: it has to be "leira'os panay," to come to be seen by Hashem because we reflect in our faces, in who we are, in how we act, his greatness. That's what we have to work on.