Viewing the Remains. Once the casket is closed it is not to be opened again unless the deceased was not previously identified and now requires identification. A "wake", i.e., visiting the funeral home on the night before the burial to comfort the mourners and to view the remains, is not a Jewish custom. The Talmudic sages in Tractate Avot 4:23 wisely noted that one cannot and should “not comfort a mourner while his dead lies before him / אל תנחמנו בשעה שמתו מוטל לפניו”. Indeed, the "wake" is often reduced to a social gathering, where the bereaved family must entertain the guests for hours and engage in trivial chatter often not related to their tragedy and grief.
Embalming, preserving and cosmetically “restoring” the body by injecting it with chemicals, covering it with cosmetics, dressing it neatly, and supporting it with mechanical devices for the purpose of displaying it in a “reposing room”, or in a chapel is prohibited. The reason is that the deceased should be remembered as a living person and not as an artificial mask made presentable by cosmeticians. One should remember the person’s deeds, teachings, attitudes and accomplishments and not how the deceased looked on the deathbed.
Embalming usually requires draining of the blood, disturbance and even removal of the brain, intestines, gall bladder and other inner organs. This is similar to an autopsy and is considered to be Nivul HaMet / ניבול המת — humiliation of the dead, desecration of the image of God and, therefore, is prohibited except when unavoidable because of health and sanitation regulations that require embalming when storing and transporting the body. The sanitation considerations might be one of the reasons why Jacob (Genesis 50:2) and Joseph (Genesis 50:26) were embalmed, as demanded by the Egyptian regulations. In our time alternative methods of temporarily preserving the body, such as refrigeration and freezing, are available and will usually satisfy both Jewish law and civil authorities. In any case, permissibility of embalming or any other method of preservation should be determined by a competent rabbi.
Embalming is in fact a disservice to the deceased, since the soul cannot leave the body and the deceased cannot rest in peace until the body disintegrates. This, however, is only true of the average person, who has sinned, and does not apply to righteous people like Jacob and Joseph, who did not sin. The souls of the righteous ascend to Heaven even if their bodies remain preserved and do not decay.
Jewish law prohibits embalming a person even when embalming is specifically requested in a will. By prohibiting embalming and unnecessary delay in burial, Jewish tradition draws a very distinct line between respect for the dead and worship of the dead.