פירוש על בבא בתרא 80:9

A concealed gift - a hidden gift, to be explained

A different version: Rav Yosef says that he did not tell them to sit.... This version is difficult for the Ri. Why is the Talmud asking: what is the difference between the two versions? It is clear that they are explicitly arguing in the case where the specification as to where to write is missing. Furthermore we rule that we are concerned about unspecified deeds. If so how can he use the gift deed since he does not tell the witnesses to write it in the market outside. However, because these days it has been instituted to write in gift deeds: He told us to write it in the market and sign it outside, therefore even if he only told them to write it, he has in mind that it be written according to all rabbinical rules. But at the time of the Amoraim, they had not made this regulation, therefore he had to explicitly tell them to write it in public. And in the version of Rabenu Chanan'el it says that he told them not to sit in the open market, and this is considered unspecified, for he does not tell them to hide, but he tells them not to publicize it, and this is considered unspecified, not to publicize it, but not to hide. But if he simply tells them to write it, that is not unspecified, and is valid according to Rabenu Chanan'el. Therefore nowadays when the deed includes that he instructed the witnesses to write it in the market and sign it in the open, it is not a requirement, but only to improve the beauty of the deed. However the term unspecified does not seem to mean this.

We do not collect with it - because perhaps he already gave it to an other, or that he only intended to make the other feel indebted.

Go and hide - hide yourselves

This is the text: And there are those who say that Rav Yosef said: It is referring to a case in which the giver did not say to witnesses: Sit outdoors in the marketplace. He did not instruct them to write it in the marketplace or streets, but he simply said to them write it.

In the marketplace and outside - write it for all to see.

The difference between the two versions is in a case where his instructions were without specification - For he said to them write it, and he did not say go and hide, and he did not instruct them to write it in the marketplace and outside. According to the earlier version of Rav Yosef the deed without specification is valid, and according to the second version it is invalid, for he has to say to them write it in the marketplace, sign it outside. And in the commentary of Rabenu Chanan'el the text is that he told them not to sit in the marketplace or outside. But this cannot be correct for in that case both versions of Rav Yosef would imply that an unspecified deed is valid.