You're entering a sacred place. What do you do?
You can't just saunter in, doing nothing, as if it were (say) some big box store. It's a sacred place; going in means something.
So what do you do?
Some reach down and touch the ground. (If you're reading this, I probably don't need to tell you why you would do this.) In practice, this often means that you touch the threshold of the temple.
What comes next is up to you. Some people touch their hearts, some (with a kiss) their lips. Some touch their brows. I usually touch all three: In my heart, on my lips, in my thoughts.
Or some variation thereof. The deeply pious may bow down and kiss the Earth. Those of us who aren't as spry as we used to be may settle for kissing the doorposts of the temple. (I love the doorposts of your house, goes the old song.)
So much for entering. How do you leave a sacred place?