Translation
Many shall purify themselves and make themselves white and be refined, but the wicked will act wickedly and none will understand, but all of the wise will understand.
Paraphrase
There will be many who purify themselves until they are pure and refined by the fire of their hardships, but the evil in heart will continue to do evil things and none of them will choose to grasp the consequences of their actions, but all of those who are wise will fully understand about consequences and will choose accordingly.
THE ANSWER TO DANIEL’S QUESTION
The angel was saying something akin to this: “Daniel, I can’t answer your question in detail because only God knows the heart of each person. You are right to see that many people are not spiritually ready, but you are wrong to think they cannot endure hardship. Suffering has a way of purifying the sufferer and many will indeed do what is needed to become pure; they will be refined by the fire of their sufferings. But this will be an individual reality, distinct for each person. There will be many others who continue in their Godless ways, and they will suffer the consequences. God will sort it all out in the end because He is a just judge.”