Comprehension, language, and application

What is the grammatical effect of «لَمْ» in «لَمْ يُسْرِعْ»?

Rights of Guests and Neighbors, Worship, Sincerity, and Responsible Care (Hadith 246–252)

• Makes the verb feminine plural
• Turns a noun into a subject
• Negates and makes the imperfect verb jussive
• Becomes a vocative particle