The answer is: 1 Samuel

1 Sam 17 - The early life of David is found in 1 Samuel.

Ah, the tale of David and Goliath—such an illustrious story that transcends generations! Found in the book of 1 Samuel, this classic scripture showcases not just a teenage shepherd named David standing up to a giant, but also themes like faith, courage, and overcoming adversity that resonate with so many of us today.

David’s five smooth stones aren't just random pebbles; they symbolize his preparation and faith in something beyond himself—poetic foreshadowing to the might of belief and the inner strength individuals possess. Interestingly, Goliath's height, around nine feet, makes him an embodiment of fear and seemingly insurmountable challenges. Yet, David demonstrated that true strength doesn't come from physical size but from heart and conviction.

In ancient Near Eastern times, battles often signified more than just physical warfare; they represented the struggle of beliefs and cultures. So, David's victory was a triumph not only of skill with the sling but also of a larger narrative wherein two ways of life came face to face.

And, let’s not forget the poetic details; David’s psalms reflect his deep connection to God—reminders that before swinging that sling, he played the harp to soothe King Saul's troubled spirit. Each passage layers the richness of character and spirituality that breathes life into these ancient texts. What a faster-paced world! Even today, underdog stories keep multiplying, reminding us that anyone can overcome giants with a bit of courage!