According to David, the author of the book, he's asking God to listen to him because he's feeling very sad and needs help. He's asking God to save him from people who are being mean to him because they are stronger than he is.
Psalms 142:6: Attend unto my cry; for I am brought very low: deliver me from my persecutors; for they are stronger than I.
While Psalms 142:6 emphasizes the speaker's cry for help and sense of weakness, Philippians 4:13 expresses confidence in strength through Christ, suggesting self-sufficiency and empowerment.
Philippians 4:13: I can do all things through Christ which strengtheneth me.