The following is from the column Halachic Corner With Rav Hershel Schachter that appeared on page 23 of the 8/10/18 issue of the Jewish Press
We consider kiverei tzaddikim holy locations, so we pray to Hakadosh Baruch – not to the tzaddikim -that in the zechus of these tzaddikim He should be kind to us.
The Gemara says you’re not allowed to daven within daled amos of a kever because it’s lo’eg larash [mocking the deceased] since the meis is not able to daven. So you have to move away. Many people pray right next to the grave in the middle of the whole cemetery. That, the Gemara says, is not proper. You should daven from a distance.
Supposing one goes to Meron: If one is so inclined,is one allowed to ask a berachah directly from Rav Shimon bar Yochai?
No, he’s not alive. How can he give a berachah? You ask Hakadosh Baruch Hu that He should answer our prayers b’zechus the tanna who’s buried here ….
We assume a makom menuchas ha’tzaddikim is a holier site, so it’s like davening near a holy place. But you daven to Hakadosh Baruch Hu. The Torah has a prohibition not to be doreish al hameisim. You’re not allowed to pray to the dead.