By Avner Friedmann
Our Parshah states,
“When brothers dwell together and one of them dies and leaves no son, the wife of the deceased may not marry out to a stranger; her husband’s brother shall come to her, take her to him as a wife and perform levirate marriage. The firstborn that she bears shall perpetuate the name of his dead brother and thus his name shall not be obliterated from Israel. But if the man does not wish to take his brother’s wife, then she shall go up to the gate, to the elders, and she shall say, ‘My husband’s brother refuses to perpetuate his brother’s name in Israel, he does not want to perform levirate marriage with me.’ The elders of his town shall call for him and speak to him; then he shall stand and say, ‘I do not want to take her.’ His sister-in-law shall approach him in front of the elders, take his shoe off his foot, spit in front of him and call out proclaiming: “so shall be done to the man who does not build his brother’s house.” His name shall be called in Israel, “The house of the one whose shoe was removed!”
The mitzvah of Levirate Marriage (Yibum) is a rare exception to the laws of the Torah and as the Ramban states, is one of the mysteries of the Torah. When a husband dies childless, his brother marries his widow so she can have a son through him. Now, if the brother does not wish to go through with the marriage, an act of “Chalitza” is done. This act severs the bond created between the brother and wife of the deceased.
The interesting thing about Levirate Marriage is that under any other circumstance, a man’s wife would be absolutely forbidden to his brother. This would be a forbidden relationship which falls under the most severe Torah prohibitions. However, for the sake of Levirate Marriage, not only is the brother allowed to marry his brother’s widow, but by doing so he would be performing an important mitzvah and doing a great act of kindness (Chessed).
The Zohar explains that when a man dies childless, without having fulfilled the important mitzvah of, “Be fruitful and multiply”, the Divine Presence (Shechinah) which is the source of all the souls of Israel, does not take this soul under its wings, as it does with other souls. Thus the soul cannot find a resting place above and is in great distress. It therefore seeks respite amongst the living. Through the process of Levirate Marriage (Yibum), HaShem gives this soul a second chance, so to speak. When his brother marries his widow and brings a son into the world, the newborn son receives the soul of the deceased husband, who starts life anew and is given a new opportunity to bring children into the world. Because he has his soul, the baby boy should be named after the deceased husband. Through the act of Yibum the living brother performs an act of true kindness (Chessed shel Emet) for the deceased, by helping him to complete his role in this world. His widow now becomes his mother and his brother now becomes his father! However, if the brother refuses to marry her, Chalitza must take place. Through the process of Chalitza the widow makes the correction for her deceased husband and releases his soul from its state of unrest. The Shechinah is now ready to take him under its wings. There his soul will dwell until the resurrection of the dead, in the “World to come.” After the Chalitza his widow may be married a different man.
It is important to note that not every person who leaves this world childless must necessarily go through this process. One example is a bachelor who never married. This may be because he already had children in a previous lifetime. Therefore, his soul may have been reincarnated to correct a different spiritual lacking.
Now, in order for the soul of the deceased brother to enter the newborn child, the couple must have intimate relations solely for the sake the mitzvah and to do a kindness for the soul of the departed. There should not be any other extraneous motives or feelings. This is so much so that in the Talmud, Abba Shaul is of the opinion that if a person performs Levirate Marriage because he finds his brother’s wife to be desirable, either because of her beauty or for any other ulterior motive, such a union is considered as though they engaged in a forbidden relationship and the offspring would be close to being illegitimate, Heaven forbid. Though some of the other sages disagreed with him, this nonetheless shows us the gravity of this mitzvah. Because of this, nowadays, since we are not on the same level of purity and spirituality they were in former generations; Yibum is no longer an option. Instead, Chalitza is performed in every case.
Now, it is interesting to note that even before the giving of the Torah at Mount Sinai, Yibum was already in practice amongst the Jewish people and its spiritual benefits were known to them. This can be seen by the story of Yehuda and Tamar in the book of Genesis. That union ultimately produced the Davidic royal dynasty and will ultimately produce our righteous King Moshiach, may he come speedily, in our days.
From all the above, we see the tremendous importance of bringing children into the world. Whether one is successful or not is all in the hands of G-d, but nonetheless, we must do our part. Woe to a person who intentionally avoids this mitzvah, whether because he does not want to marry or whether he is married but does not want the burden of children. The path to the correction of his soul will be a difficult one. First of all, he will suffer a lonely existence in this world, especially in his old age and when his time finally comes to depart from this world, no one will mourn for him. Moreover, he will leave no one behind him to help his soul in the afterworld, as we learn that even after the soul departs, “a son merits his father” through saying the Kaddish prayer, giving tzedakah (charity) and generally performing mitzvot and acts of loving kindness.
Albeit, HaShem has mercy upon all his creatures and makes sure that, ultimately, everyone has the opportunity to correct himself, as the verse states, “No one will be banished from Him.” Therefore, even a person who willfully avoided having children and died childless may be given another chance by HaShem through reincarnation.
 Deuteronomy 25:5-10
 Rabbi Moshe ben Nachman of Gerona, commonly referred to as Nachmanides.
 Leviticus 18:16
 Zohar VaYeshev 186b-188b, Chukat 180a-181a, Mishpatim 104a-104b, Pinchas 218a, Tikkunei Zohar-Tikun 26, Zohar Chadash-Ki Teitzei 281a
 Talmud, Yevamot 109a
 Genesis 38:6-30
 Sotah 10b
 Samuel II, 14:14