Burial Customs and the Bible:
Proper burial was important in ancient religions, so its only natural that they receive attention throughout the Bible. Use of above-ground tombs in caves is prominent and several such tombs can still be found close to Jerusalem. An important story connected to Abraham was his insistence on finding a proper cave in which he could bury his wife, Sarah.
Care of the Body Before Burial:
Egyptians embalmed many of their dead while other Near Eastern cultures often cremated the bodies of the deceased. Zoroastrians left the dead to be consumed by vultures and later collected the bones. Jews, however, rejected all of this and insisted that the body be kept intact for burial, wrapped in linen and anointed with oil. Greeks often placed the dead in coffins, but the Jews only rarely did this, preferring instead to leave a body open on a stone slab.
What Was Secondary Burial?:
One thing which the Jews did share with the Zoroastrians was differential treatment of the body and the bones. A body left on an open stone slab in a tomb or cave will eventually decompose. The bones left over would either be placed in a common burial chamber further back in the cave when a new body is placed on the slab (the likely meaning of phrases like to sleep with ones ancestors), or they would be collected into an ossuary for preservation by the family.
It was normal for burial to proceed as quickly as possible in the Near East, given what the heat and sun could do to a body. Jewish custom required that a body be buried the same day or, if it was the sabbath, immediately after the sabbath period was over.