Muhammad—may Allah bless him and grant him peace—Allah said (1):
“But whoever disbelieves, let not his disbelief grieve you.” [Surah Luqmān: 23]
And He Most High said:
“And do not grieve over them or be distressed by what they plot.” [Surah al-Nahl: 127]
And He said:
“So let not their words grieve you.” [Surah Yā Sīn: 76] (2)
“So do not let yourself perish in sorrow over them.” [Surah Fātir: 8]
We also find (3) that He Most High said:
“We certainly know that what they say grieves you.” [Surah al-An‘ām: 33]
He has thus told us that He knows (4) that His Messenger (5) is grieved by what they say, and He forbade him to grieve. They are therefore bound (6) to apply to the grief of the Messenger of Allah—may Allah bless him and grant him peace—the very same objection they raised (7) concerning Abū Bakr’s grief (8).
And yes (9), the grief of the Messenger of Allah—may Allah bless him and grant him peace—over the disbelieving words they uttered was an act of obedience to Allah before Allah forbade him to grieve, just as (10) Abū Bakr’s grief was an act of obedience to Allah before He forbade him to grieve; and Abū Bakr did not grieve
(1) Al-Fisal: “… yanhā 'anhu, wa-lam yakun taqaddama ilayhi nahyun 'an al-huzn, wa-amāma Rasūl Allāh sallā Allāhu 'alayhi wa-sallam fa-inna Allāha 'azza wa-jalla qāla” (… forbids it; no prohibition against grief had previously been addressed to him; and before Allah’s Messenger—may Allah bless him and grant him peace—Allah, Mighty and Majestic, said).
(2) Al-Fisal adds “inna al-'izzata li-Allāhi jamī'an” (all might belongs to Allah), followed by “wa-qāla ta'ālā” (And He Most High said).
(3) Before this word, al-Fisal quotes verse 6 of Surah al-Kahf: “fa-la'allaka bākhi'un nafsaka …” (Perhaps you will destroy yourself …).
(4) The passage between the two asterisks is omitted from S and B.
(5) Al-Fisal, 4:222: “wa-qālahu aydan fī al-An'ām. Fa-hādhā Allāhu ta'ālā akhbaranā annahu ya'lamu anna Rasūl Allāh sallā Allāhu 'alayhi wa-sallam” (He also said it in al-An'ām. Thus Allah Most High has told us that He knows that Allah’s Messenger—may Allah bless him and grant him peace—…).
(6) Al-Fisal: “wa-nahāhu 'azza wa-jalla 'an dhālika nassan, fa-yalzamuhum” (And He, Mighty and Majestic, explicitly forbade him to do that; they are therefore bound …).
(7) Al-Fisal: “… wa-sallam alladhī nahāhu Allāhu ta'ālā 'anhu ka-alladhī arādū …” (… and grant him peace—[the grief] which Allah Most High forbade him, just as with what they intended …).
(8) Al-Fisal: “… sawā'an sawā'an” (… exactly the same).
(9) B alone: “wa-na'lamu” (and we know).
(10) Al-Fisal: “qabla an yanhāhu Allāhu 'azza wa-jalla, wa-mā hazina 'alayhi al-salām ba'da an nahāhu rabbuhu ta'ālā 'an al-huzn, kamā kāna” (before Allah, Mighty and Majestic, forbade him; and he—peace be upon him—did not grieve after his Lord Most High forbade him to grieve, just as …).