Will a person be sinful for delaying prayer – knowing that it is permissible to delay it unintentionally due to sleep – because of his prior frustration at missing it at its original time?

It is obligatory to hasten to prayer immediately upon waking up. It is not permissible to remain in bed after waking up and letting the optional time for prayer expire. The sin is not in sleeping, but rather in being awake, for the Prophet, peace and blessings be upon him, said: "There is no negligence in sleep, but negligence is in wakefulness." Deliberately delaying prayer until the end of its necessary time without a valid excuse is impermissible and is considered one of the grave sins.