Sahih Bukhari Volume 7, Book 62, Hadith Number 145.

Narrated By Ibn ‘Abbas : That ‘Umar entered upon Hafsa and said, “O my daughter! Do not be misled by the manners of her who is proud of her beauty because of the love of Allah’s Apostle for her.” By ‘her’ he meant ‘Aisha. ‘Umar added, “Then I told that to Allah’s Apostle and he smiled (on hearing that).”