King James Version (KJV)
1 And the Lord appeared unto him in the plains of Mamre: and he sat in the tent door in the heat of the day;
2 And he lift up his eyes and looked, and, lo, three men stood by him: and when he saw them, he ran to meet them from the tent door, and bowed himself toward the ground,
3 And said, My Lord, if now I have found favour in thy sight, pass not away, I pray thee, from thy servant:
4 Let a little water, I pray you, be fetched, and wash your feet, and rest yourselves under the tree:
5 And I will fetch a morsel of bread, and comfort ye your hearts; after that ye shall pass on: for therefore are ye come to your servant. And they said, So do, as thou hast said.
6 And Abraham hastened into the tent unto Sarah, and said, Make ready quickly three measures of fine meal, knead it, and make cakes upon the hearth.
7 And Abraham ran unto the herd, and fetcht a calf tender and good, and gave it unto a young man; and he hasted to dress it.
8 And he took butter, and milk, and the calf which he had dressed, and set it before them; and he stood by them under the tree, and they did eat.
9 And they said unto him, Where is Sarah thy wife? And he said, Behold, in the tent.
10 And he said, I will certainly return unto thee according to the time of life; and, lo, Sarah thy wife shall have a son. And Sarah heard it in the tent door, which was behind him.
11 Now Abraham and Sarah were old and well stricken in age; and it ceased to be with Sarah after the manner of women.
12 Therefore Sarah laughed within herself, saying, After I am waxed old shall I have pleasure, my lord being old also?
13 And the Lord said unto Abraham, Wherefore did Sarah laugh, saying, Shall I of a surety bear a child, which am old?
14 Is any thing too hard for the Lord? At the time appointed I will return unto thee, according to the time of life, and Sarah shall have a son.
15 Then Sarah denied, saying, I laughed not; for she was afraid. And he said, Nay; but thou didst laugh.
16 And the men rose up from thence, and looked toward Sodom: and Abraham went with them to bring them on the way.
I used to wonder why the Bible mentions Sarah laughed, and later she gave birth to son Isaac, whose name is derived from laughter. When couples have problems, they could always resolve it in two ways. They could resolve it in such a way both of them feel angry and are bitter afterwards, or they could resolve it, so both of them end up laughing afterwards.
Couples who are friends of each other, usually, without any major issues that might accrue afterwards, they usually end up laughing afterward. This is because if both partners are friends of each other, there is usually understanding between them.
There is power in unity. Christ is the head of the man, the man is the head of the woman, and God is the head of Christ. This long line is a thread of unity, a thread based in unity. One of the names of God is the figure one, or unity. Unity is very important in any marriage relationship.
Understanding is both spiritual, and physical. Usually, when a married couple believe their sins have been washed by the Christ, when they believe their past, present, and future sins have been washed in Christ, this is a tremendous basis for unity in Christ. It does not mean a married couple might agree on every issue, though, they might still have a unity of purpose, one that lends for a great power of unity, in prayer and in action.