1) Some say that one should give his child only names mentioned in the Torah from Avraham Avinu and later. But we do not call ourselves by names mentioned in the Torah before Avraham Avinu.

2) Some limit the above specifically to naming one’s child after a person mentioned in the Torah before Avraham Avinu - this should not be done. For example, one should not name his son Noach specifically after the Noach mentioned in the Torah. But, if he names his son Noach for some other reason, or for no particular reason, it is permitted.

3) Others say that we need not be particular about this, and that one is permitted to give his child even names mentioned in the Torah before Avraham Avinu.