From Sahih Muslim (Hadith 2562):
This hadith has been narrated on the authority of Ibn Abi Aufa (Allah be pleased with him) through another chain of transmitters (but with a sight alteration of words):In this hadith transmitted by one of the narrators (neither these words are found): During the month of Ramadan." nor his statement:" And the night prevails from that side (the eastern side)." (These words are found in the narration of) Hushaim only
Reference: Muslim 2562