1 Corinthians 3:10-15 is a big one. Talks about our works being tested by fire, some will go through and not be burned up but others will be burned, they will be saved, but as through fire. This gives the idea that depending on ones works and life, they can suffer loss but still be saved when their work is examined which is when they die. so the suffering is temporary since they are saved
The next is 2 Maccabees 12:38-46. This talks about Judah Maccabees making atonement for the dead that they may be absolved for their sins. But they are already dead, therefore showing that those who are dead and in sin can still be atoned for, and the prayers and offerings of the living can help. So, again, the dead are suffering since they need absolution while dead, but it is temporary since it can be absolved. Those in Hell cannot be saved or absolved like the case with these two passages
And then the idea of temporal punishment also comes from just everyday living. We see punishments that are temporary. If Christ died to take away all punishment, then we wouldn’t have any punishments in our lives as Christians. But, as everyone knows, we do get punished for things even as Christians, such as speeding, or showing up late for work, and the list goes on. We see then that Christ didn’t die for temporary punishments but died for our eternal punishment.
Also, we don’t just need the Bible to answer. We can look at the Tradition of the Church and see temporal punishment, which is Purgatory, as a teaching of the Church throughout the centuries. See this website for quotes from Church Fathers:
https://www.catholicbridge.com/catholic/purgatory-church-fathers.php
God Bless
