Tafsir of Yunus 10:97

إن الذين حقت عليهم كلمت ربك ﻻ يومنون ولو جاءتهم كل آية حتى يروا العذاب اﻻليم

Truly, those, against whom the Word (wrath) of your Lord has been justified, will not believe. Even if every sign should come to them, until they see the painful torment. meaning they would not believe in a way that they might benefit from that belief. This is when they believe at a time one may not be able to benefit from his belief. An example is when Musa prayed against Fir`awn and his chiefs, saying:

ربنا اطمس على أمولهم واشدد على قلوبهم فﻼ يومنوا حتى يروا العذاب اﻻليم

Our Lord! Destroy their wealth, and harden their hearts, so that they will not believe until they see the painful torment. (10:88) And Allah said:

ولو أننا نزلنا إليهم المليكة وكلمهم الموتى وحشرنا عليهم كل شء قبﻼ ما كانوا ليومنوا إﻻ أن يشاء الله ولكن أكثرهم يجهلون

And even if We had sent down unto them angels, and the dead had spoken unto them, and We had gathered together all things before their very eyes, they would not have believed, unless Allah willed, but most of them behave ignorantly. (6:111) Allah then said: