I'm well aware the the British lied when they told the Arabs supporting them that they would have independence post war, given they had already agreed with France to divide the area.
https://www.irishtimes.com/news/world/middle-east/betrayal-of-arabs-after-first-world-war-set-stage-for-turbulent-century-1.1840067
Betrayal of Arabs after first World War set stage for turbulent century
However, that has nothing to do with giving Palestinian land to Jews as a homeland 29 years later, and Britain had abdicated to the UN to decide it's fate, after being defeated by Jewish terrorists, the Stern gang.
https://www.britannica.com/topic/Stern-Gang
Extremely anti-British, the group repeatedly attacked British personnel in Palestine and even invited aid from the Axis powers.