What does the second phrase do in «أَمَدَّكُمْ بِمَا تَعْلَمُونَ ... بِأَنْعَامٍ وَبَنِينَ»?

Chapter Eight: Ijaz, Itnab and Musawah — Brevity, Amplification and Balance

• Changes to an unrelated topic
• Negates the first clause
• Clarifies the initial generality
• Deletes the subject