The Bavli, Shabas 46:
Rav Aviya came to Rava's house; his boots were gross with clay. He set [them] on a bed in front of Rava. Rava minded; [Rava] wanted to bother him. [Rava] said to him: Why did Raba and Rav Yosef both say a naphtha lamp may also be moved [on Shabas after it's extinguished]? [Rav Aviya] answered: Because it is fit for covering a receptacle with. [Rava countered:] If so, all the pebbles in the courtyard may be moved, as they are fit for covering a receptacle with? [Rav Aviya answered:] This [lamp] has the status of a receptacle; those [pebbles] do not have the status of a receptacle. [And] hasn't it been taught that bracelets, nose rings, and rings are like any receptacle that may be moved in a courtyard, and Ula said why, because they have the status of a receptacle? Here, too, because it has the status of a receptacle.
Rav Nachman bar Yitzchak said: Blessed be the Merciful that Rava did not shame Rav Aviya.
- Is there anything to Rav Nachman bar Yitzchak's blessing beyond the usual desire that no one be shamed? Why would be bad for Rava to shame Rav Aviya in this story beyond the usual reasons?
- Why does the Bavli see fit to include this blessing of Rav Nachman bar Yitzchak's?
(I suspect that the answer to #1, if affirmative, may help clarify #2 as well.)