I am surprised by the answer given by UmH. He says
It is permissible to touch a slave woman when buying her. This is
customary and necessary as it is done to detect any physical defects
or to verify qualities which are used to appraise the price which is
going to be paid. Just like one can examine an expensive house,
vehicle, furniture, dress or even fruits and vegetables which they
wish to buy, they can also examine the slaves whom they intend to buy.
I believe according to Quran and Sunnah, a master cannot touch a female captive without her permission or marriage. But here it is said a non master can touch a woman even before he buys her. isn't the person a stranger for her ? what is the ruling of touching a strange woman(non mahram) in Islam, that too without her consent ? Equating woman with a commodity like vehicle, furniture etc is defaming woman and not giving the status that Islam give to woman.
Now that slavery is not there, these type of rulings will help non-muslims degrade Islam, where as these rulings have nothing to do with Quran and Sunnah. And in the event of sects like ISIS, who claim that it is ok to reintroduce slavery, gain power, they will use these to unnecessarily torture woman.