Prioritizing family in giving tzedakah: Bava Metzia 71a
The biblical imperative to help family members in any need: Ketuvot 52b
Rabbi Yochanan said he should have overridden the biblical imperative to help family members, because helping them could make him, as an important person, seem to be guilty of nepotism in their litigation [even though he was not a judge in the case]: Ketuvot 52b
