Allah consoles His Messenger for his sorrow over the idolators because they would not believe and keep away from him
He also said:
[فَلاَ تَذْهَبْ
نَفْسُكَ عَلَيْهِمْ حَسَرَتٍ]
(So destroy not yourself in sorrow for them.) [35:8]
[وَلاَ تَحْزَنْ
عَلَيْهِمْ]
(And grieve not over them.) [16:127]
[لَعَلَّكَ بَـخِعٌ
نَّفْسَكَ أَلاَّ يَكُونُواْ مُؤْمِنِينَ ]
(It may be that you are going to kill yourself with grief, that they do not
become believers.) [26:3] meaning, maybe you will destroy yourself with your
grief over them. Allah says:
[فَلَعَلَّكَ بَـخِعٌ
نَّفْسَكَ عَلَى ءَاثَـرِهِمْ إِن لَّمْ يُؤْمِنُواْ بِهَـذَا الْحَدِيثِ]
(Perhaps, you would kill yourself in grief, over their footsteps, because
they believe not in this narration.) meaning the Qur'an.
[أَسَفاً]
(in grief) Allah is saying, `do not destroy yourself with regret.' Qatadah
said: "killing yourself with anger and grief over them.'' Mujahid said: "with
anxiety.'' These are synonymous, so the meaning is: `Do not feel sorry for them,
just convey the Message of Allah to them. Whoever goes the right way, then he
goes the right way only for the benefit of himself. And whoever goes astray,
then he strays at his own loss, so do not destroy yourself in sorrow for
them.'