أَمَدَّكُمْ بِمَا تَعْلَمُونَ أَمَدَّكُمْ بِأَنْعَامٍ وَبَنِينَ
He provided you with things you well know; He provided you with livestock and sons. (Ash-Shu‘ara 26:132–133)
«بِمَا تَعْلَمُونَ» initially refers to blessings as a whole. The following expression names prominent examples. First comes a general recognition of bounty; then explicit instances make it more vivid.
Benefit: the initial generality prepares the listener for a detailed clarification. The second statement unfolds the first rather than opening a disconnected subject.