لِلَّذِينَ ٱسْتَجَابُوا۟ لِرَبِّهِمُ ٱلْحُسْنَىٰ وَٱلَّذِينَ لَمْ يَسْتَجِيبُوا۟ لَهُۥ لَوْ أَنَّ لَهُم مَّا فِى ٱلْأَرْضِ جَمِيعًا وَمِثْلَهُۥ مَعَهُۥ لَٱفْتَدَوْا۟ بِهِۦٓ
"For those who answer their Lord there is the best. As for those who do not answer Him: if all that is in the earth were theirs, and the like of it with it, they would offer the whole of it as a ransom."
The measure must be recorded: mā fi'l-arḍi jamīʿan wa mithlahu maʿah — the whole of the earth and the like of it again.
The same measure was treated at al-Zumar 39/47, and it was recorded there: an amount that goes beyond what exists — and even so it is not accepted. I rely on that treatment.
And the difference between the two verses is worth recording: in al-Zumar the ransom was offered to escape the punishment; in al-Raʿd the context of the ransom is not having answered the call.
I record this as my own reading, and its ground is the first half of the verse: what was given to the other side was al-ḥusnā (the best), and the only thing asked in return was istijāba (answering the call) — not a price, that is, but a response. The scene of the ransom shows what follows from that response not having been given.