Narrated Abu Huraira may Allah be pleased with him, reported:
A man came to Allah's Apostle and said,
"O Allah's Apostle! Who is more entitled to be treated with the best companionship by me?" The
Prophet said, "Your mother." The man said. "Who is next?" The Prophet
said, "Your mother." The man further said, "Who is next?" The Prophet
said, "Your mother." The man asked for the fourth time, "Who is next?"
The Prophet said, "Your father. "

Sahih Bukhari (Volume 8, Book 73, Number2
عن ‏ ‏أبي هريرة ‏ ‏رضي الله عنه ‏ ‏قال ‏:
(‏جاء ‏ ‏رجل ‏ ‏إلى رسول الله ‏ ‏صلى الله عليه وسلم ‏
‏فقال يا رسول الله ‏ ‏من أحق الناس بحسن صحابتي قال أمك قال ثم من قال ثم أمك قال ثم من قال ثم أمك قال ثم من قال ثم أبوك)
صحيح البخاري, الأدب, رقم 5514