What is the ruling on completing a full recitation of the Quran (khatm al-Qur'an) when moving to a new house or buying a new car?

It was not reported that the Messenger of Allah, peace and blessings be upon him, or his companions, would complete a reading of the Qur'an (khatm al-Qur'an) upon moving to a new house or purchasing something new. However, if one does so out of gratitude to Allah for the blessing, or in compliance with the Hadith: "Do not make your houses graves," then their intention is good. But if they do so considering it a Sunnah, then it is not permissible due to the lack of evidence supporting it.