How was Isaac mocked in the Bible?

Answer 1

The story is in Genesis 21 where his half-brother, Ishmael was mocking him perhaps over the fact that it would be Isaac who would receive the birthright promise and not Ishmael who was Abram's firstborn. New International Version account:

Hagar and Ishmael Sent Away

8 The child grew and was weaned, and on the day Isaac was weaned Abraham held a great feast. 9 But Sarah saw that the son whom Hagar the Egyptian had borne to Abraham was mocking,10 and she said to Abraham, "Get rid of that slave woman and her son, for that woman's son will never share in the inheritance with my son Isaac."

11 The matter distressed Abraham greatly because it concerned his son.12 But God said to him, "Do not be so distressed about the boy and your slave woman. Listen to whatever Sarah tells you, because it is through Isaac that your offspring[b] will be reckoned.13 I will make the son of the slave into a nation also, because he is your offspring."