To forget one’s ancestor’s is to be a brook without a source, a tree without root

Similar sayings:

Forget injuries, never forget kindnesses Forget injuries, never forget kindnesses
Forget the favors you have given; remember those received Forget the favors you have given; remember those received
When the mantis hunts the locust, he forgets the shrike that’s hunting him When the mantis hunts the locust, he forgets the shrike that’s hunting him
We forget even incense in easy times; come hard times, we embrace the Buddha’s feet We forget even incense in easy times; come hard times, we embrace the Buddha’s feet
When the tree falls, the shadow flies When the tree falls, the shadow flies

Chinese sayings and proverbs