From
苏轼《
稼说送张琥》(Su Shi, Northern Song):
博观而约取,
厚积而薄发 (Observe widely but take sparingly; accumulate deeply but release sparingly). Written as advice to his friend Zhang Hu on the agricultural metaphor — a field must be deeply turned and well-rested before it yields. A gold-standard motto in Chinese education, often inscribed in schools and libraries.