The Jews did believe in burial as opposed to burning. Burning was considered a desecration of the body and was reserved for criminals either while alive (Genesis 38:24; Leviticus 20:14; 21:9) or after death (Joshua 7:15, 25). The burning of bodily remains was considered an outrage, as when Moab "burned the bones of the king of Edom into lime" (Amos 2:1). Another reason for burial was to fulfill the judgment on man because of Adam's fall: "for dust thou art, and unto dust shalt thou return" (Genesis 3:19). Burial was considered the proper way to fulfill this judgment.
However, burial did not necessarily refer to the digging of a hole in the ground and the placing of the body into the dirt as we normally do today. That was probably done at times. However, the Bible record (both in Old and New Testaments) speaks most of burial in tombs. These tombs could be natural caves (as in the cave of Machpelah where Abraham buried his family - Genesis 23:9, 19), or hewn chambers (as the place where Jesus was buried; called a "new tomb" - Matthew 27:60), or even an erected mausoleum. Since the body is placed in the earth, this is considered burial. Genesis 23:19 records, "Abraham buried Sarah his wife in the cave of the field of Machpelah before Mamre." The Bible clearly calls the placing of a body in a cave a burial.
I was not familiar with your stated purpose for burial; that is, to speed the return of the soul to God. However, I found a quote that might explain this concept. Rabbi Ben Kaphra, who lived in the centuries after Christ, is quoted as saying: "For three days the spirit hovers about the tomb, if perchance it may return to the body. But, when it sees the fashion of the countenance changed, it retires and abandons the body." I would speculate that a burial in earth might more hastily convince the spirit that the body needs to be deserted. But that is only my speculation. In ancient times and in the warmth of Bible lands, the burial would of necessity take place within 24 hours. This practice was followed in other lands for centuries but is not practiced everywhere now. That practice might also be suggested by a desire to encourage the spirit's return to God. However, most of these practices are later traditions and would not affect the practices of Bible times.
