Deuteronomy 25:5-10 Deuteronomy 25:5-10  If brothers dwell together, and one of them die, and have no child, the wife of the dead shall not marry without to a stranger: her husband’s brother shall go in to her, and take her to him to wife, and perform the duty of an husband’s brother to her.
 And it shall be, that the firstborn which she bears shall succeed in the name of his brother which is dead, that his name be not put out of Israel.
 And if the man like not to take his brother’s wife, then let his brother’s wife go up to the gate to the elders, and say, My husband’s brother refuses to raise up to his brother a name in Israel, he will not perform the duty of my husband’s brother.
 Then the elders of his city shall call him, and speak to him: and if he stand to it, and say, I like not to take her;
 Then shall his brother’s wife come to him in the presence of the elders, and loose his shoe from off his foot, and spit in his face, and shall answer and say, So shall it be done to that man that will not build up his brother’s house.
 And his name shall be called in Israel, The house of him that has his shoe loosed.
American King James Version×addresses a statute that had unique application to ancient Israel. Now called the law of levirate marriage, from the Latin word levir, meaning “brother-in-law,” it stated that if a married man died without children, his widow was to be married to his brother (her brother-in-law), or his nearest of kin if there was no brother, and the first child of this new union was to be regarded as the offspring of the deceased husband (compare Genesis 38:9 Genesis 38:9And Onan knew that the seed should not be his; and it came to pass, when he went in to his brother’s wife, that he spilled it on the ground, lest that he should give seed to his brother.
American King James Version×; Matthew 22:24 Matthew 22:24Saying, Master, Moses said, If a man die, having no children, his brother shall marry his wife, and raise up seed to his brother.
American King James Version×).
This was to be done so that the name of the dead brother would “not be blotted out of Israel.” It also ensured that the widow would continue to be provided for. Obviously, then, this could have put certain economic strain on the levir, particularly if he already had a family, as he had to provide for a wife and for the raising of a child until that child was old enough and independent enough to carry on the name of his “father” on his own. The nearest of kin could, however, refuse to take the widow as his wife, although he would have to go through a humiliating process in which everyone saw his selfishness in being more concerned for himself than for his extended family (verses 9-10). In the case of Ruth in the biblical book bearing her name, her deceased husband’s closest relative refused to marry her, so that Boaz, the next in line on the kinship list, was free to do so (Ruth 3:13 Ruth 3:13Tarry this night, and it shall be in the morning, that if he will perform to you the part of a kinsman, well; let him do the kinsman’s part: but if he will not do the part of a kinsman to you, then will I do the part of a kinsman to you, as the LORD lives: lie down until the morning.
American King James Version×; Ruth 4:1-9 Ruth 4:1-9  Then went Boaz up to the gate, and sat him down there: and, behold, the kinsman of whom Boaz spoke came by; to whom he said, Ho, such a one! turn aside, sit down here. And he turned aside, and sat down.  And he took ten men of the elders of the city, and said, Sit you down here. And they sat down.  And he said to the kinsman, Naomi, that is come again out of the country of Moab, sells a parcel of land, which was our brother Elimelech’s:  And I thought to advertise you, saying, Buy it before the inhabitants, and before the elders of my people. If you will redeem it, redeem it: but if you will not redeem it, then tell me, that I may know: for there is none to redeem it beside you; and I am after you. And he said, I will redeem it.  Then said Boaz, What day you buy the field of the hand of Naomi, you must buy it also of Ruth the Moabitess, the wife of the dead, to raise up the name of the dead on his inheritance.  And the kinsman said, I cannot redeem it for myself, lest I mar my own inheritance: redeem you my right to yourself; for I cannot redeem it.  Now this was the manner in former time in Israel concerning redeeming and concerning changing, for to confirm all things; a man plucked off his shoe, and gave it to his neighbor: and this was a testimony in Israel.  Therefore the kinsman said to Boaz, Buy it for you. So he drew off his shoe.  And Boaz said to the elders, and to all the people, You are witnesses this day, that I have bought all that was Elimelech’s, and all that was Chilion’s and Mahlon’s, of the hand of Naomi.
American King James Version×).
The law of levirate marriage is not applicable in the Church today. One reason is that a literal application of it would often require a converted brother-in-law to marry an unconverted sister-in-law, or vice versa, which would be contrary to 1 Corinthians 7:39 1 Corinthians 7:39The wife is bound by the law as long as her husband lives; but if her husband be dead, she is at liberty to be married to whom she will; only in the Lord.
American King James Version×and 2 Corinthians 6:14 2 Corinthians 6:14Be you not unequally yoked together with unbelievers: for what fellowship has righteousness with unrighteousness? and what communion has light with darkness?
American King James Version×. Also, if the brother-in-law were already married, the application of this law would violate the biblical teaching (discussed earlier) that a man is to be the husband of only one wife. As this is specifically mandated in the New Testament for ministers and deacons, it is understood to be binding upon all men in the Church.