"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." (Using translation from Nasāʾī 3712)
«لَا تَحِلُّ الرُّقْبَى وَلَا الْعُمْرَى فَمَنْ أَعْمَرَ شَيْئًا فَهُوَ لَهُ وَمَنْ أَرْقَبَ شَيْئًا فَهُوَ لَهُ»