Proverbs 2:17

who forsaketh the guide of her youth, and forgetteth the covenant of her God;

Jeremiah 3:4

Wilt thou not from this time cry unto me, My father, thou art the guide of my youth?

Proverbs 5:18

Let thy fountain be blessed; and have joy of the wife of thy youth.

Ezekiel 16:8

And I passed by thee, and looked upon thee, and behold, thy time was the time of love; and I spread my skirt over thee, and covered thy nakedness; and I swore unto thee, and entered into a covenant with thee, saith the Lord Jehovah, and thou becamest mine.

Ezekiel 16:59-60

For thus saith the Lord Jehovah: I will even deal with thee as thou hast done, who hast despised the oath, and broken the covenant.

Malachi 2:14-16

Yet ye say, Wherefore? Because Jehovah hath been a witness between thee and the wife of thy youth, against whom thou hast dealt unfaithfully: yet is she thy companion, and the wife of thy covenant.

Treasury of Scripture Knowledge

Summary

Which forsaketh the guide of her youth, and forgetteth the covenant of her God.

Bible References

The guide

Proverbs 5:18
Let thy fountain be blessed; and have joy of the wife of thy youth.
Jeremiah 3:4
Wilt thou not from this time cry unto me, My father, thou art the guide of my youth?

Forgetteth

Ezekiel 16:8
And I passed by thee, and looked upon thee, and behold, thy time was the time of love; and I spread my skirt over thee, and covered thy nakedness; and I swore unto thee, and entered into a covenant with thee, saith the Lord Jehovah, and thou becamest mine.
Malachi 2:14
Yet ye say, Wherefore? Because Jehovah hath been a witness between thee and the wife of thy youth, against whom thou hast dealt unfaithfully: yet is she thy companion, and the wife of thy covenant.

General references

Exodus 20:14
Thou shalt not commit adultery.
Leviticus 15:20
And everything that she lieth upon in her separation shall be unclean; and everything that she sitteth upon shall be unclean.
Numbers 5:12
Speak unto the children of Israel, and say unto them, If any man's wife go astray, and commit unfaithfulness against him,