Sirach 51:26
Ben Sira, Ecclesiasticus24 Why do you say you are lacking in these things, and why do you endure such great thirst? 25 I opened my mouth and said, Acquire wisdom for yourselves without money. 26 Put your neck under her yoke, and let your souls receive instruction; it is to be found close by. 27 See with your own eyes that I have labored but little and found for myself much serenity. 28 Hear but a little of my instruction, and through me you will acquire silver and gold.
Didache 6:2
1 Be careful that no one leads you astray from this Way of teaching, for those who do so are teaching you without God. 2 If you can bear the full burden of the Lord's requirements, you will be perfect; but if you cannot, do what you can. 3 Regarding food, eat what you can tolerate, but always avoid food that has been offered to idols, as it represents the worship of lifeless gods.
Notes and References
"... The use of ζυγόν ('yoke') twice in the famous 'Heilsanruf' in Matthew 11:29-30 has been much debated, but the parallel with Sirach 51:26 and with other Wisdom literature suggest that here too the point at issue is the Law and its interpretation. Reference to the Law as a yoke is well attested in Rabbinic Judaism, as in the saying of Nehunya b. Ha-Kanah: 'He that takes upon himself the yoke of the Law, from him shall be taken the yoke of the kingdom and the yoke of worldly care' (Pirkei Avot 3:5). The only reference to 'yoke' in the Qumran literature is to the yoke of the Kittim (1QpHab 6:6). While Ba. does not have a parallel to Didache 6:2, it is concerned with the problem of the applicability of the Jewish Law to Gentile Christian converts ... [it] sounds like a polemic against Didache 6:2 and rejects the 'yoke of necessity' in favor of the 'new law of our Lord Jesus Christ' ..."
Draper, Jonathan Alfred A Commentary on the Didache in the Light of the Dead Sea Scrolls and Related Documents (p. 135) St. John's College, 1983