mazaar

Q: The following verse from Surah Kahf which is verse 21 ,The English translation is as follows : "And thus We made their case known, that they might know that the promise of Allah is true, and that there can be no doubt about the Hour. (Remember) when they (the people) disputed among themselves about their case, they said: "Construct a building over them; their Lord knows best about them," (then) those who won their point said: "We verily, shall build a mosque over them."

The barelvi Sect believe that this verse makes building a mazaar shareef permissible in Islam. I am no scholar of deen so I want to know your views on this ayaat and the barelvi sect use of it. Looking forward to your response inshallah