The book of Proverbs is the book of wisdom. This book is attributable to Solomon. It gives us instructions for a life of good and warnings about evil. This is the time to pray, be in silence and meditate.
Strength is not physical strength alone, but mental and spiritual strength. All strength originates in Spirit.
When we learn to be still (meditation), we gain access to God through spiritual discernment and “spiritual discernment is a faculty of the Soul, the spirit, which is within you [and without].” Joel Goldsmith, “Consciousness Transformed.”