Question:
why is yitzchak named after the laughter if sarah was reprimanded for laughing unless we are naming after the laeghter of avraham which was good thing
Answer:
Hello,
Yitzchak was called His name because Sarah said, whoever will hear about this will rejoice, Bereishis 21-6 see Rashi). The tzchok that was problematic was in perek 18, where the tzchok was mixed with an element of doubt that it will actually happen, and incident which happened a while before Yitzchok was born.
As a side point Yitzchok was the symbol of din, avoda. Nevertheless, his name was Yitzchok, after the word to rejoice. This shows us that a person who is serving Hashem properly, can and will also be a person who is very happy, like Yitzchok and his name.
Best wishes
