Sitting shiva is first specifically mentioned in the Mishnah.
The Mishnah was composed of rulings of Jewish sages, many of whom were Jesus' contemporaries, so it makes sense that it was already an old practice at the time of the crucifixion.
According to Jewish law, only parents, spouses, children and brothers and sisters of the immediate family are required to sit shiva.
The practice is considered biblical and is traced to the seven-day mourning period observed by Joseph over his father in Genesis 50:10.
So, far from being "baloney", DonQ's thesis is certainly plausible.
I agree with you. Very plausible.
The first stage is the period between death and burial. During this time the mourners are excused from all religious duties in order to prepare the burial.
After the burial, a period of seven days of mourning – the “shiva” begins. During this time the mourner does not leave his house...
Luke 23:
53Then he took the body down from the cross and wrapped it in a long linen cloth and laid it in a new tomb that had been carved out of rock.54This was done late on Friday afternoon, the day of preparation for the Sabbath.55 As his body was taken away, the women from Galilee followed and saw the tomb where they placed his body.56Then they went home and prepared spices and ointments to embalm him. But by the time they were finished it was the Sabbath, so they rested all that day as required by the law...
Luke 24 1But very early on Sunday morning the women came to the tomb, taking the spices they had prepared (to embalm Him)
The shiva wouldn't have started until they were satisfied Jesus had been given a proper Jewish burial WHICH INCLUDED THE EMBALMING (with spices and ointments)