Where does “dua” come from?

dua (Proto-North Sarawak) comes from Proto-Malayo-Polynesian duha, from Proto-Austronesian *duha, from Proto-Austronesian duSa — two.

Ancestry of “dua”, step by step

StepLanguageWordMeaning
1Proto-Malayo-Polynesianduhatwo
2Proto-Austronesian*duha—
3Proto-AustronesianduSatwo
Every word from Proto-Austronesian duSa →Every word from Proto-Austronesian *duha →Every word from Proto-Malayo-Polynesian duha →