Which prophcey was the Ethiopian reading in Isaiah when Phillip approached him?

The Ethiopian eunuch was reading from Isaiah 53, specifically verses that describe the suffering servant, who is led like a sheep to the slaughter and does not open his mouth. This passage speaks of the servant's humility and sacrifice, which puzzled the eunuch, prompting him to seek understanding. Philip then explained how this scripture referred to Jesus, leading to the eunuch's conversion.