Sunan an Nasai
3712
Sahih+2

(A different chain) from Sufyan, from Abu Az-Zubair, from Tawus, from Ibn 'Abbas, who said:"Ruqba and 'Umra are not permissible; whoever is given something on the basis of 'Umra, it is his, and whoever is given something on the basis of Ruqba, it is his

SahihAbu Ghuddah
SahihAl-Albani