Sirach 31:16
Ben Sira, Ecclesiasticus14 Do not reach out your hand for everything you see, and do not crowd your neighbor at the dish. 15 Judge your neighbor's feelings by your own, and in every matter be thoughtful. 16 Eat what is set before you like a well brought-up person, and do not chew greedily, or you will give offense. 17 Be the first to stop, as befits good manners, and do not be insatiable, or you will give offense. 18 If you are seated among many persons, do not help yourself before they do.
Clement of Alexandria The Instructor 2.7
PaedagogusEat, it is said, like a man what is set before you. Be the first to stop for the sake of regimen; and, if seated in the midst of several people, do not stretch out your hand before them. You must never rush forward under the influence of gluttony; nor must you, though desirous, reach out your hand till some time, inasmuch as by greed one shows an uncontrolled appetite. Nor are you, in the midst of the repast, to exhibit yourselves hugging your food like wild beasts; nor helping yourselves to too much sauce, for man is not by nature a sauce-consumer, but a bread-eater. A temperate man, too, must rise before the general company, and retire quietly from the banquet. For at the time for rising, it is said, be not the last; haste home. The twelve, having called together the multitude of the disciples, said, It is not meet for us to leave the word of God and serve tables. If they avoided this, much more did they shun gluttony.
Notes and References
"... The eighty-fifth of the Apostolical Canons gives a list of the books of the Hebrew Canon, and adds the first three books of the Maccabees and the Wisdom of Sirach; these last four are not, however, included in the Canon, though the Wisdom of Sirach is specially recommended for the instruction of the young. Again, in the Apostolical Constitutions, 6:14, 15, quotations from Sirach are given with the same formula as those from the books of the Hebrew Canon, but in the list given in 2:57 of the same work, there is no mention of any of the books of the Apocrypha ... The evidence of Clement of Alexandria is conflicting; in his Paedagogus he quotes very often from Sirach, and speaks of it as 'scripture', from which it would evidently appear that he regarded it as canonical Scripture; but, according to Eusebius, Clement reckoned Sirach among the 'Antilegomena', for in speaking of Clement's works he mentions the Stromateis, or 'Medleys', and says: 'He quotes in them passages from the disputed Scriptures, the so-called Wisdom of Solomon, for example, and of Jesus the son of Sirach, and the Epistle to the Hebrews, and those of Barnabas, Clement, and Jude ..."
Charles, R. H. The Apocrypha and Pseudepigrapha of the Old Testament (p. 299) Oxford University Press, 1913