Sahih al-Bukhari, 435 (9th Century)
May Allah curse the Jews and the Christians, for they have taken the graves of their Prophets as places of worship.
The Custom Spreads
Doresh el HaMeitim - Inquiring of the Dead
Praying Inside a Cemetery
Judaism Stresses Life, Not Death
Halakhic Man, R. Joseph B. Soloveitchik, p. 31
Judaism has a negative attitude toward death: a corpse defiles; a grave defiles; a person who has been defiled by a corpse is defiled for seven days and is forbidden to eat any sacred offerings or enter the Temple; a Nazirite who has been defiled by a corpse cancels his previous count and must carry out the shaving of his head for defilement and bring an offering; the priests of God are forbidden to defile themselves with the dead....
Authentic Judaism as reflected in halakhic thought sees in death a terrifying contradiction to the whole of religious life. Death negates the entire magnificent experience of halakhic man....
Praying Through Intermediaries
Should We Visit Cemeteries At All?
Halakhic Man, R. Joseph B. Soloveitchik, p. 36
The Gaon of Vilna, R. Joseph Dov Soloveitchik, his son, R. Hayyim, his grandson, R. Moses, R. Elijah Pruzna [Feinstein] never visited cemeteries and never prostrated themselves upon the graves of their ancestors. The memory of death would have distracted them from their intensive efforts to study the Torah.
Potential for Inappropriate Worship
Are They Even Accurate?
...[Herod] gave orders to kill all the boys in Bethlehem and its vicinity who were two years old and under... Then what was said through the prophet Jeremiah was fulfilled: "A voice is heard in Ramah, weeping and great mourning, Rachel weeping for her children..."
So What Can We Do?