أَمَدَّكُمْ بِأَنْعَامٍ وَبَنِينَ
He provided you with livestock and sons.
Amadda is a past verb with an understood subject; -kum is its object; bi-an‘amin is a prepositional phrase, and banin is coordinated with an‘am. The complete verbal clause specifies the earlier general mention of favors.
The wāw in wa-banin coordinates words within one phrase, not the second sentence with the first. Coordination of individual words must be distinguished from rhetorical wasl of whole sentences.