A knife sharpener in a dream represents someone who teaches people skills, sagacity and adroitness.

A knife sharpener in a dream also represents sobriety, a dignified bearing of adversities, or he could represent a vile person, a trouble maker, or a decisive person.... Islamic Dream Interpretation

(Blade) A pencil sharpener in a dream represents a good son who is envied by people. Seeing a pencil sharpener in a dream means that one will be gifted with such a beautiful son. In a dream, a pencil sharpener also represents a writer or an author. Ifone sees himself holding a pencil sharpener in a dream, it means reconciliation with a woman with whom he has been separated for sometime.... Islamic Dream Interpretation

1. Sharpening an object may be an attempt to enhance one’s abilities, intelligence, etc.

2. Someone sharpening a knife is someone getting ready to defend oneself. ... New American Dream Dictionary