This quote is saying that small, seemingly insignificant things have a much larger impact than you may think. One grain of sand contains an entire world of possibilities, and even something as small as a wildflower can contain something as grand as a whole heaven. If you truly take the time to look, you can find whole universes inside the smallest of things. You also have the power to hold infinity in the palm of your hand – meaning that any lack of understanding need not hinder you. And, even if our lives are thought to be finite, in each moment we can attain eternity – that is to say, find true joy and purpose in the here and now.