What are the six repetitions in the book of proverbs

My son, if thou wilt receive my words, and hide my commandments with thee; So that thou incline thine ear unto wisdom, and apply thine heart to understanding; Yea, if thou criest after knowledge, and liftest up thy voice for understanding; If thou seekest her as silver, and searchest for her as for hid treasures; Then shalt thou understand the fear of the Lord, and find the knowledge of God.