2 sentences

1. 他一向严于律己，是大家学习的榜样。

   tā yī​xiàng yán​yú​lǜ​jǐ, shì dà​jiā xué​xí de bǎng​yàng.

   He has always been strict with himself and is a role model for everyone to learn from.

   Source: Dong Chinese Dictionary

2. 在处理人际关系时，我们要严于律己，宽以待人。

   zài chǔ​lǐ rén​jì guān​xi shí, wǒ​men yào yán​yú​lǜ​jǐ, kuān​yǐ​dài​rén.

   In handling interpersonal relationships, we should be strict with ourselves and lenient with others.

   Source: Dong Chinese Dictionary