Lech L'Shalom Rabbinic Approaches to Saying Goodbye

And Rabbi Avin HaLevi said: One who takes leave from another should not say to him: Go in peace, but rather, he should say: Go to peace. As we see that, on the one hand, Jethro said to Moses: “Go to peace” (Exodus 4:18), and Moses ascended and was successful. On the other hand, David said to his son, Absalom: “Go in peace” (II Samuel 15:9), and Absalom went and was ultimately hanged.

On the topic of proper preparation for prayer, the Sages taught: One may neither stand to pray from an atmosphere of sorrow nor from an atmosphere of laziness, nor from an atmosphere of laughter, nor from an atmosphere of conversation, nor from an atmosphere of frivolity, nor from an atmosphere of purposeless matters. Rather, one should approach prayer from an atmosphere imbued with the joy of a mitzva. Similarly, a person should neither take leave of another from an atmosphere of conversation, nor from an atmosphere of laughter, nor from an atmosphere of frivolity, nor from an atmosphere of purposeless matters. Rather, one should take leave of another from involvement in a matter of halakha. As we found in the books of the Bible dealing with the early prophets, that they would conclude their talks with words of praise and consolation. And so Mari, the grandson of Rav Huna, son of Rabbi Yirmeya bar Abba, taught in a baraita: One should only take leave of another from involvement in a matter of halakha, so that, consequently, he will remember him; whenever he recalls the one from whom he took leave, he will think well of him because of the new halakha that he taught him.