Muslim liberals often reject traditional interpretations of Islamic law, which allows Ma malakat aymanukum and slavery. They say that slavery opposed Islamic principles which they believe to be based on justice and equality and some say that verses relating to slavery or "Ma malakat aymanukum" now can not be applied due to the fact that the world has changed, while others say that those verses are totally misinterpreted and twisted to legitimize slavery. In the 20th century, South Asian scholars Ghulam Ahmed Pervez and Amir Ali argued that the expression "ma malakat aymanukum" should be properly read in the past tense. When some called for reinstatement of slavery in Pakistan upon its independence from the British colonial rule, Pervez argued that the past tense of this expression means that the Quran had imposed "an unqualified ban" on slavery.