Former NBA star Amar'e Stoudemire -- who converted to Judaism and spent several years playing basketball in Israel -- sounded off on Hamas in an emotional video ... saying point blank, "If y'all support it, f*** you!"
The 40-year-old posted the clip to his social media page over the weekend ... blasting the militant terrorist group as "cowards" -- while strongly urging people to condemn the org.'s actions.
"I woke up this morning with some disturbing news out of Israel that Hamas are kidnapping children, putting them in cages, killing women, killing the elderly.