How can Christians criticize Muhammad for not making a will when he prescribed it for his followers?

Muhammad's failure to make a will, despite prescribing it for his followers, presents a significant inconsistency in his teachings. The Hadiths clearly show that he did not leave a will, and his reasoning—that prophets do not have heirs—contradicts the Quranic evidence that prophets like Zakariya and David had heirs. In fact, the Quran explicitly states that it is a duty for the righteous to write a will for their relatives, which further emphasizes the expectation of leaving a legacy. This inconsistency raises questions about the reliability of Muhammad's teachings and his role as a prophet, as true prophets would be expected to adhere to the principles they teach. Additionally, the Shiite interpretation aligns with the understanding that it is obligatory for Muslims to leave a will, further highlighting the discrepancy in Muhammad's actions versus his teachings.