Sahih Bukhari Volume 4, Book 52, Hadith Number 305.
Narated By Um Khalid : (The daughter of Khalid bin Said) I went to Allah’s Apostle with my father and I was Nearing a yellow shirt. Allah’s Apostle said, “Sanah, Sanah!” (‘Abdullah, the narrator, said that ‘Sanah’ meant ‘good’ in the Ethiopian language). I then started playing with the seal of Prophethood (in between the Prophet’s shoulders) and my father rebuked me harshly for that. Allah’s Apostle said. “Leave her,” and then Allah’s Apostle (invoked Allah to grant me a long life) by saying (thrice), “Wear this dress till it is worn out and then wear it till it is worn out, and then wear it till it is worn out.” (The narrator adds, “It is said that she lived for a long period, wearing that (yellow) dress till its color became dark because of long wear.”)