If we sharpen, it shows that there are aggressive feelings within us. If it is someone else who sharpens, that person wants to harm us.
Dream dictionary: Sharpen dream meanings
…To sharpen an object when you are dreaming, can be interpreted as the need of the flexibility of the dreamer’s mind. Sharpening of something in the dream is like sharpening of the mind in the life. It means that you need to be better in what you’re doing or thinking. Alternatively, the dream about sharpening represents the lack of the dreamer’s quality to adapt to the requests of others. Maybe you are a little bit to egoistic. You should consider of the overall picture of your dream. Think what will be best interest for you and for others, than just thinking about your needs….
If you dream of sharpen object, then it means that there is something you are afraid of or have a very strict personality. Maybe you should be more sensitive and indulgent towards other people opinions. Make sure you think about others as much as you think about yourself.