Musannaf Ibn Abi Shayba 21:651

Habeeb ibn Habeeb narrated to us, from Abu Ishaq, from al-Hakam, who said: Whoever hears the caller calling for the establishment of the prayer and says: "O Allah, Lord of this perfect call and the established prayer, grant Muhammad his request on the Day of Resurrection," will be among those for whom he (Muhammad) will intercede.