What is the legal ruling on who has the right to lead the funeral prayer: the legal guardian son or the mosque's imam, and does the ruling differ if the deceased bequeathed that a specific person pray over them?

Scholarly opinions vary regarding who has the most right to lead the funeral prayer (Salat al-Janazah). The Hanafis believe in prioritizing the ruler or his deputy, then the judge, then the Imam of the neighborhood. As for the Malikis and Hanbalis, they prioritize the one whom the deceased designated to lead the prayer, then the governor or prince. The Shafi'is, according to the more sound opinion, prioritize the guardian (wali), interpreting the hadith "A man should not lead prayer in another's domain of authority" as not applying to the funeral prayer. Some scholars prefer prioritizing the Imam if the funeral prayer is performed in the mosque, citing the action of Al-Husayn ibn Ali, who let Sa'id ibn Al-As lead the prayer for his brother Al-Hasan (may Allah be pleased with them both), saying: "Were it not a Sunnah, I would not have put you forward."