Why did the proportion of divine will in the story of Moses and Al-Khidr differ among the three situations mentioned in Surat Al-Kahf, followed by His saying: "And I did not do it of my own accord"?

The different phrases in the story of Al-Khidr with Moses (peace be upon him) indicate the proper etiquette in attributing matters to Allah Almighty. Al-Khidr attributed the flaw in the ship to himself, saying, "So I wished to make it defective" (fa-aradtu an aeebaha), because a defect is not a good thing. He attributed the replacement of the boy for his parents to the plural form, saying, "So We intended that their Lord should substitute for them" (fa-aradna an yubdilahuma rabbuhuma), because he did that by Allah's command. He attributed the intention of good for the two orphans to Allah, saying, "So your Lord intended that they reach their maturity" (fa-arada rabbuka an yablugha ashuddahuma). This aligns with the etiquette of the prophets in attributing all good to Allah and not attributing evil to Him, as stated in the Hadith Qudsi: "And all good is in Your hands, and evil is not attributed to You."