What is the meaning of "khawf" (lit. "fear") in this āyah?

Imām Ibn al-Jawzī (d. 597/1201) summarized the scholars' opinions in his book "Zād al-Masīr" as follows:

1. It refers to knowledge. This implies that injustice has already occurred.
2. It refers to the emotion of fear, i.e. that injustice may occur.