Nearby ayahs help place verse 13:30 in sequence and meaning.
ٱلَّذِينَ ءَامَنُوا۟ وَتَطْمَئِنُّ قُلُوبُهُم بِذِكْرِ ٱللَّهِ ۗ أَلَا بِذِكْرِ ٱللَّهِ تَطْمَئِنُّ ٱلْقُلُوبُ
Those who have believed and whose hearts are assured by the remembrance of Allah. Unquestionably, by the remembrance of Allah hearts are assured."
ٱلَّذِينَ ءَامَنُوا۟ وَعَمِلُوا۟ ٱلصَّـٰلِحَـٰتِ طُوبَىٰ لَهُمْ وَحُسْنُ مَـَٔابٍ
Those who have believed and done righteous deeds - a good state is theirs and a good return.
وَلَوْ أَنَّ قُرْءَانًا سُيِّرَتْ بِهِ ٱلْجِبَالُ أَوْ قُطِّعَتْ بِهِ ٱلْأَرْضُ أَوْ كُلِّمَ بِهِ ٱلْمَوْتَىٰ ۗ بَل لِّلَّهِ ٱلْأَمْرُ جَمِيعًا ۗ أَفَلَمْ يَا۟يْـَٔسِ ٱلَّذِينَ ءَامَنُوٓا۟ أَن لَّوْ يَشَآءُ ٱللَّهُ لَهَدَى ٱلنَّاسَ جَمِيعًا ۗ وَلَا يَزَالُ ٱلَّذِينَ كَفَرُوا۟ تُصِيبُهُم بِمَا صَنَعُوا۟ قَارِعَةٌ أَوْ تَحُلُّ قَرِيبًا مِّن دَارِهِمْ حَتَّىٰ يَأْتِىَ وَعْدُ ٱللَّهِ ۚ إِنَّ ٱللَّهَ لَا يُخْلِفُ ٱلْمِيعَادَ
And if there was any qur'an by which the mountains would be removed or the earth would be broken apart or the dead would be made to speak, [it would be this Qur'an], but to Allah belongs the affair entirely. Then have those who believed not accepted that had Allah willed, He would have guided the people, all of them? And those who disbelieve do not cease to be struck, for what they have done, by calamity - or it will descend near their home - until there comes the promise of Allah. Indeed, Allah does not fail in [His] promise.
وَلَقَدِ ٱسْتُهْزِئَ بِرُسُلٍ مِّن قَبْلِكَ فَأَمْلَيْتُ لِلَّذِينَ كَفَرُوا۟ ثُمَّ أَخَذْتُهُمْ ۖ فَكَيْفَ كَانَ عِقَابِ
And already were [other] messengers ridiculed before you, and I extended the time of those who disbelieved; then I seized them, and how [terrible] was My penalty.