Why did the wording of the divine will differ between "your Lord intended" and "so We intended" in the story of Moses and Al-Khidr in Surat Al-Kahf?

The secret in the righteous man's expression, "Then your Lord intended," is that reaching maturity (al-ashudd) can only be ordained by Allah. It is also a matter of good manners to attribute good to Allah and evil to others. Therefore, regarding the killing of the boy, he said: "So we intended that their Lord should substitute for them one better than him in purity and nearer to mercy," thereby attributing the intention to himself.