It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him), in a marfu' (Prophetic) report: "The Greatest Name of Allah, by which, when He is called upon, He answers, is in three surahs of the Qur'an: al-Baqarah, Al Imran and Ta Ha."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7894