(yes, a sword will pierce through your own soul also), that the thoughts of many hearts may be revealed.”
Luke 2:35

This explains the Walmart trip. The sword is the Word.

For the word of God is living and powerful, and sharper than any two-edged sword, piercing even to the division of soul and spirit, and of joints and marrow, and is a discerner of the thoughts and intents of the heart. Heb 4:12