King James Bible

THINE, pronominal adj. Thy; belonging to thee; relating to thee; being the property of thee. It was formerly used for thy, before a vowel.

Then thou mightest eat grapes thy fill, at thine own pleasure. Deuteronomy 32:1.

But in common usage, thy is now used before a vowel in all cases.

The principal use of thine now is when a verb is interposed between this word and the noun to which it refers. I will not take any thing that is thine thine is the kingdom, and the power, and the glory.

In the following passage, thine is used as a substitute for thy righteousness.

I will make mention of thy righteousness, even of thine only. Psalms 71:2.

In some cases, it is preceded by the sign of the possessive case, like nouns, and is then also to be considered as a substitute.

If any of thine be driven out to the utmost parts of heaven-- Deuteronomy 30:2.

It is to be observed that thine like thou, is used only in the solemn style. In familiar and common language, your and yours are always used in the singular number as well as the plural.