Ketubot 109B

אבל הדיינין חותמים אף על פי שלא קראוהו.

However, judges do sign a document even though they have not read it, as they are merely certifying the signatures without relating to the content of the document at all.

עשאה סימן לאחר. אמר אביי: לא שנו אלא לאחר, אבל לעצמו ⁠— לא איבד את זכותו.

§ The Mishnah taught that if someone established a field as a marker for another field, everyone agrees that he has lost his right to contest its ownership. Abaye said: They taught this only in a case where he stated this in a document unrelated to the field in question, which was written for another person. However, if he established it as a marker for himself, when he was buying a different field owned by the person who is in possession of the contested field, he has not lost his right.

דאמר: אי דלא עבדי ליה הכי לא הוה מזבין לה ניהלי, מאי אית לך למימר? איבעי לי למימסר מודעא ⁠— חברך חברא אית ליה, וחברא דחברך חברא אית ליה.

The reason is that the claimant can say: Had I not done this act of writing that the field belongs to him, he would not have sold me this other field. What have you to say against this argument? Will you say that I should have put out a notice and declared in the presence of witnesses that I am forced to write this way in the contract? I was concerned about doing this, as your friend has a friend and your friend’s friend has a friend. In other words, it is hard to keep an announcement of this kind secret, and ultimately my notice would have become public knowledge and would have reached the owner of the field himself, and he would have refused to sell me the other tract of land.