John Calvin Commentary Deuteronomy 24:5

"When a man taketh a new wife, he shall not go out in the host, neither shall he be charged with any business: he shall be free at home one year, and shall cheer his wife whom he hath taken." — Deuteronomy 24:5 (ASV)

The immunity given here has as its purpose the awakening of that mutual love which may preserve the conjugal fidelity of husband and wife. For there is a danger that if a husband departs from his wife immediately after marriage, the bride, before she has become thoroughly accustomed to him, might be too prone to fall in love with someone else. A similar danger affects the husband, for in war and other expeditions, many things occur which tempt men to sin.

God, therefore, intends for the love of husband and wife to be fostered by their association for a whole year, so that mutual confidence may be established between them, and they may afterwards continually beware of all unchastity.

But that God should permit a bride to enjoy herself with her husband is no small proof of His indulgence.

Undoubtedly, the lust of the flesh must affect the connection of husband and wife with some amount of sin. Yet God not only pardons it but also covers it with the veil of holy matrimony, so that what is sinful in itself might not be imputed as such; indeed, He spontaneously allows them to enjoy themselves. What Paul says is consistent with this instruction:

Let the husband render to his wife due benevolence: and likewise also the wife to the husband. Do not defraud one another, except with consent for a time, that you may give yourselves to fasting and prayer (1 Corinthians 7:3, 5).