It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) slept until he (peace and blessings be upon him) snored, then got up, prayed and did not perform ablution.
(b) Likewise is the hadith of Ibn Abbas (may Allah be pleased with them both) about spending the night, in which this addition does not occur.
(c) His (peace and blessings be upon him) sleep was while lying down, and he (peace and blessings be upon him) did not perform ablution; this was something specific to him, as this hadith indicates.
Abu Khalid al-Dalani alone narrated that addition.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 600