Complex sentence: After the boycott was lifted, when another nephew, Abu Salama, came to Abu Talib asking for protection, and when the Makhzum clan protested about this, Abu Lahab supported his brother.
Split into simpler sentences: After the boycott was lifted, another nephew, Abu Salama, came to Abu Talib asking for protection. When the Makhzum clan protested about this, Abu Lahab supported his brother.