苏轼 wrote it for
张琥, who had passed the imperial examination in the same year as him. It contrasts a rich farmer, who lets his fields rest, sows in good time and harvests only ripe grain, with a poor farmer who works his small plot without a break. Learning, Su Shi says, also needs time to ripen, and he asks Zhang Hu to pass the advice on to his brother
苏辙.