Answer:
That his father had some savings kept away from his failed business
Step-by-step explanation:
Gregor's father had a business which failed,so Gregor heard his father had had some savings from that business.
Gregor had just woken up from sleep, so he overhead His father explaining the financial status of his failed business to Gregor's Mother and his sister.
His father had the old habit of reading out loud during his study. His father opined that he wants the family to get over the bad occurrence and move on
This question can be referenced from a book titled "Franz Kafka"