WHEN two are sitting at the table, the elder one commences to eat first and the younger one after him; and if the younger commences first, he is a glutton. It happened that R. Aqiba prepared a meal for his disciples consisting of two dishes of meat, one half-roasted and the other one well cooked. The half-roasted was served first; the most sensible of them took the whole piece into his one hand and with his other hand he tried to break off some part of it, but could not, and he placed it back and ate bread alone. One of them, who was less sensible, took the whole piece and bit off a piece. Said R. Aqiba to him: "Not so, my son. Put thy foot on it in the dish, and then you will probably succeed better." Finally, the well-cooked meat was served, and they ate and were satisfied. Then said R. Aqiba to them: "My children, I did all that to see whether you had refined manners."
One shall not eat before the fourth hour, neither shall he take a bath prior to that hour. Hot water in large quantities is injurious to one's body, but in small ones is beneficial. The same is the case with wine. Three things are equal one to the other: wisdom, fear of God, and modesty. One shall not rejoice among those who are weeping, neither shall he weep among those who rejoice; he shall not be awake among those who are asleep, nor shall he sleep among those who are awake; he shall not be standing among those who are seated, nor shall he be seated among those who are standing. This is the rule: One shall not have different manners from those of his friends and of people in general among whom he is.
Sources: Sacred Texts