נֶ֚פֶשׁ כִּֽי־תִמְעֹ֣ל מַ֔עַל וְחָֽטְאָה֙ בִּשְׁגָגָ֔ה מִקָּדְשֵׁ֖י יְהוָ֑ה וְהֵבִיא֩ אֶת־אֲשָׁמ֨וֹ לַֽיהוָ֜ה אַ֧יִל תָּמִ֣ים מִן־הַצֹּ֗אן בְּעֶרְכְּךָ֛ כֶּֽסֶף־שְׁקָלִ֥ים בְּשֶֽׁקֶל־הַקֹּ֖דֶשׁ לְאָשָֽׁם׃
If any one commit a trespass, and sin through error, in the holy things of the LORD, then he shall bring his forfeit unto the LORD, a ram without blemish out of the flock, according to thy valuation in silver by shekels, after the shekel of the sanctuary, for a guilt-offering.
Pirkei Avot
Antigonus a man of Socho received [the oral tradition] from Shimon the Righteous. He used to say: do not be like servants who serve the master in the expectation of receiving a reward, but be like servants who serve the master without the expectation of receiving a reward, and let the fear of Heaven be upon you.