Maliks Muwatta Book 20, Hadith Number 129.
Section : Starting with Safa in the Say.
Yahya related to me from Malik from Nafi that he heard Abdullah ibn Umar making dua on Safa saying, “O Allah, You have said, ‘call on Me – I will answer you’ and You do not break Your promise. So I am asking You, in the same way that You have guided me to Islam, not to take it away from me, and that You make me die while I am muslim.”