Where does “ia” come from?

ia (Samoan) comes from Proto-Polynesian ia, from Proto-Oceanic ia, from Proto-Eastern Malayo-Polynesian ia, from Proto-Central-Eastern Malayo-Polynesian ia, from Proto-Malayo-Polynesian (si-)ia, from Proto-Austronesian (si-)ia — he, him, his, she, her, it.

ia (Samoan): he, she; Precedes a name to mark it as a direct...