Cited from a tahqiq — print number not yet locked
Narrator: Abu Musa al-Ash‘ari (r.a.)
مَنْ قَرَأَ فِي صُبْحٍ أَوْ مَسًى {قُلِ ادْعُوا اللَّهَ أَوِ ادْعُوا الرَّحْمَنَ} إِلَى آخِرِ السُّورَةِ لَمْ يَمُتْ قَلْبُهُ ذَلِكَ الْيَوْمَ وَلَا فِي تِلْكَ اللَّيْلَةِ
The Prophet (peace be upon him) said: “Whoever recites in the morning or the evening {Say: Call upon Allah or call upon al-Rahman} to the end of the surah, his heart will not die that day nor that night.”
Grade
Attributed to al-Daylami from Abu Musa, without a grade
Al-Suyuti
Jami‘ al-Ahadith no. 23452; Kanz al-‘Ummal (al-Ikmal) no. 2594
Both compilations name the source “(al-Daylami)” only, without issuing a ruling.
Cited without stating a grade
Sheikh Redwan Muhammad Redwan
Himpunan Risalah, footnote no. 80
Acting on a weak report in fada’il al-a‘mal
Imam al-Nawawi writes in al-Adhkar: “The scholars among the hadith specialists, the jurists and others have said: it is permitted and encouraged to act, in matters of merit and of encouragement and warning, upon a weak hadith — so long as it is not fabricated (mawdu‘).” As for rulings such as the lawful and unlawful, sale, marriage and divorce, these may rest only on a sahih or hasan report.
The conditions Ibn ‘Allan states in al-Futuhat al-Rabbaniyya (1/84): (1) the report is neither fabricated nor severely weak; (2) it falls under an established general principle; and (3) when acting on it one does not hold it to be established from the Prophet (peace be upon him), but acts out of precaution.
Al-Adhkar, al-Nawawi — section on acting upon a weak hadith
Notes
The text above is copied from the compilations of al-Suyuti and al-Muttaqi al-Hindi, not from Musnad al-Firdaws itself — the well-known recension of al-Firdaws carries no chains. Its printed number in al-Firdaws is not locked.
Qawiy has not found a ruling from any named muhaddith for this chain. Its grade is still pending review.