Oldest precursor to letter S aka Samekhi was found in nine-letter Canaanite text unearthed in Israel

At biblical site, researchers discover ABCs of how alphabet came to be  The Times of Israel
Source Oldest precursor to letter S found in nine-letter Canaanite text unearthed at Lachish, in central Israel; discovery 'another piece in the puzzle' of alphabet's development, researcher says