Select list elements based on other list
Select[listA,MemberQ[listB,#[[1]]]&]
{{"a", 1, 3}, {"e", 4, 4}}
You can also use Cases
:
Cases[{Alternatives @@ listB, __}] @ listA
{{"a", 1, 3}, {"e", 4, 4}}
You can use an association:
take = Lookup[AssociationThread[#[[All, 1]] -> #], #2, Nothing] &;
take[listA, listB]
(* {{"a", 1, 3}, {"e", 4, 4}} *)