What is the ruling on following a funeral procession that will be buried in unlawful graves, such as those that are raised more than 30 cm above the ground?

Witnessing a funeral, praying over the deceased, and burying them carries immense virtue. Whoever prays over a deceased person and follows their funeral until they are buried will receive two qirats of reward, each qirat being like Mount Uhud. It is recommended for men to follow the funeral procession until burial, while it is disliked for women to follow, though not forbidden.

The Sunnah (definition) is for the grave to be raised only about a handspan (shibr) and to be mounded. Mounding is better than flattening. The grave should not be raised more than this amount, as it was reported that Ali (may Allah be pleased with him) would not leave any elevated grave without leveling it. A shibr is equivalent to 23.1 centimeters, and a slight increase up to 30 centimeters is permissible and does not render the burial un-Islamic. Sheikh Ibn Baz was asked about this and replied that there is no harm in a slight increase of pebbles and sprinkling water on the grave to preserve its soil and integrity.

It is forbidden to build structures over graves, plaster them, or sit on them. Raising graves excessively is prohibited. Constructing domes and shrines over graves and turning them into mosques are forbidden acts that lead to great corruption, including the ignorant believing in their power to bring benefit and ward off harm, which is shirk (definition).