The following quote is from Padma Purana, Kriyāyogasāra-Khaṇḍa, Chapter 3 - The Story of King Manobhadra, verses 47b-51:
47b-51. These two large-armed ones, are really (men) of meritorious vows and a great heart. If there is any bad act seen among all acts, it is not giving a present to a brāhmaṇa, after picking it on their own. O king, due to that act only, these two went to hell. The giver who after picking a gift does not give it to a brāhmaṇa, goes to a fierce hell causing fear to all beings. The giver would not remember the gift; the receiver does not ask for it. Both live in hell as long as the moon and the sun are (in the sky). Therefore, O lord, these two, snatching the wealth of a brāhmaṇa, are great sinners.
The meaning is not clear to me. Can someone help? What was the sin of the two candalas exactly - not giving charity to brahmanas, stealing from brahmanas or something else?