If you're talking about a coin that looks like this: (shown in the related link) or similar to it, it's given to members of AA (Alcoholics Anonymous) after they've been successfully sober for X amount of time.
The coin with the inscription "to thine own self be true" likely refers to a line from Shakespeare's play Hamlet. It is often interpreted as a reminder to stay true to oneself and be authentic in one's actions and decisions. This quote emphasizes the importance of self-awareness and integrity.
In the quotation 'To thine own self be true' thine is used for the word 'your'. It says 'Be true to yourself'.
The quote "To thine own self be true" was written by Shakespeare. This appears in a speech by Polonius in Hamlet. This is NOT in the Bible.
Translating to contemporary English "Be true to yourself."
Summerland - 2004 To Thine Self Be True 1-7 is rated/received certificates of: Argentina:13
He's showing his true colors. To thine own self be true.
Grammar. "Thine" is used before a word beginning with a vowel (like the difference between "a" and "an"). Shakespeare wrote "thine," of course. (Elizabethan grammar was a flexible thing, but not in this case.)
Frasier - 1993 To Thine Old Self Be True 7-20 is rated/received certificates of: Canada:PG (video rating)
90210 - 2008 To Thine Own Self Be True 2-10 is rated/received certificates of: Netherlands:6 USA:TV-14
Season 1 episode 7 it is called "to thine self be true"
"This above all: to thine own self be true."
Summerland - 2004 To Thine Self Be True 1-7 was released on: USA: 6 July 2004 Germany: 18 February 2006 France: 8 May 2006
I think Shakespeare said it best: "To thine own self be true."