So you might think it means to go into the shul or the beis medrash and to open up the Gemara or the Tehillim and to get to work. That’s what the shul is for after all. No; Dovid didn’t say that; He said, “The one thing I want is shivti! I want to sit in the House of Hashem.” Of course, once you’re sitting you might as well accomplish something too; but even if you don’t, just walking up the steps, bringing your body into the shul and sitting, that alone is an accomplishment.
I’ll prove it to you. Let’s say right after the tefillah you realize you forgot your coat in the shul. You’re in a hurry; you have to catch the train so you want to rush back in to get your coat. Oh no! You can’t do that! You’ll walk into the house of Hashem just for your own purpose?! You have no business coming in here just for your coat. And so you’re stuck now outside the shul.
So the Gemara gives you an eitzah. It tells you that when you walk into the shul, the first thing is you have to sit down. Sit down for a minute in the mikdash me’at. It’s a halacha – you have to sit down for a little bit and then you can take your coat. And the Rambam (Tefillah 11:9) explains that ‘sitting down in the beis haknesses is a mitzvah on its own, as the possuk states ך∆ ̇י≈ב י≈ב¿ׁ ֹ̆יו י≈ר¿ׁ ַ̆‡ – How fortunate are those who sit in Your house’.
