Psalm 19’s first part is about the perfectness of the world, from the big things that makes the world what it is, to the most minor details that happen with perfect accuracy.
– All of that, without saying anything indicates HASHEM’s being. The whole creation sings HASHEM praises, just by ..being. “The heavens recite the glory of God, and the sky tells of the work of His hands.“… (Psalm 19,2)
At the link above you can find the recording from my Cellphone for Tehilim 13,6 that we sang together.
Our discussion in a nut shell:
It seems that this chapter was written by king David after some sort of a defeat in battle.
The first verses (Psalm 13, 2-3) he expresses his frustration and pain of being abandoned by HaShem. Metaphorically G-d doesn’t see him anymore, ignores his existence. In continuation for this comment, we mentioned that in times of distress, people tend to feel lost as a child that his/her concern is the parents..and the worst punishment is their ignorant from him/her. (Then also feel left alone by G-d – where is He? Why did He do that to me?..)