Psalms 136:7

לְעֹשֵׂה אוֹרִים גְּדֹלִים כִּי לְעוֹלָם חַסְדּוֹ

To the One Who made great lights, for His mercy endures forever.

This verse is cited in the brachos leading up to Shema. The “great lights” are the sun and the moon, as are specified in verses 8-9. Rashi tells us that the reason David included these “great lights” in this Psalm of thanks is because a person’s life is dependent upon them.