Sayyiduna Anas bin Malik (may Allah be pleased with him) reports that the Prophet (peace and blessings be upon him) said: "Whoever offers forty prayers in my mosque in such a way that not a single prayer of his is missed, freedom from Hell, freedom from punishment and freedom from hypocrisy are recorded for that person." (Allamah al-Haythami says:) I say: Imam al-Tirmidhi recorded part of it.
Imam Ahmad recorded this, and Imam al-Tabarani recorded it in al-Mu'jam al-Awsat, and its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الحج / 5878
Hadith Gradingمحدثین:إسنادہ صحیح
Hadith Takhrij«اخرجه احمد فى المسند ( 155/3) ، أخرجه مسند أحمد برقم: 12173، وأخرجه المعجم الأوسط للطبراني برقم: 5440»