How can we reconcile the two noble hadiths: "There is no negligence in sleep" and "As for the first man you came upon whose head was being crushed with a rock, he is the man who takes the Quran but then rejects it, and sleeps through the obligatory prayer"?

There is no contradiction between the hadith "There is no negligence in sleep" and the hadith regarding punishing one who sleeps through prayer. The first applies to someone who is overcome by sleep without negligence, while still being keen on prayer; thus, there is no sin upon him. As for the second, it applies to the negligent person who does not care about prayer and sleeps after its time has begun, despite being able to wake up; such a person is sinful and deserves punishment. A Muslim must take measures to stay awake and be diligent in performing prayers on time.