Pronoun
An emphasized form of the personal pronoun of the second person; -- used as a subject commonly with thou; as, thou thyself shalt go; that is, thou shalt go, and no other. It is sometimes used, especially in the predicate, without thou, and in the nominative as well as in the objective case.
Source: Webster's dictionaryHe who has injured thee was either stronger or weaker than thee. If weaker, spare him; if stronger, spare thyself. Seneca
Content thyself to be obscurely good. When vice prevails, and impious men bear sway, the post of honoris a private station. Joseph Addison
Revere thyself, and yet thyself despise. Edward Young
Keep counsel of thyself first. English Proverb
When thou seest thy house in flames, go warm thyself by it. Spanish Proverb
I do not tell thee what thou art, thou wilt tell it thyself. Spanish Proverb