'Signed' in the Bible

I signed the deed and sealed it, and called in witnesses, and weighed out the money on the scales.

and I gave the purchase deed to Baruch the son of Neriah, the son of Mahseiah, in the sight of Hanamel my uncle’s son and in sight of the witnesses who signed the purchase deed, in the presence of all the Jews who were sitting in the court of the guard.

So King Darius signed the document, that is, the injunction.

Now when Daniel knew that the document was signed, he went into his house (now in his roof chamber his windows were open toward Jerusalem); he continued to get down on his knees three times a day, praying and giving thanks before his God, as he had been doing previously.

Then they approached and spoke before the king regarding his injunction, “Have you not signed an injunction that anyone who petitions (prays to) any god or man except you, O king, within the designated thirty days, is to be thrown into the den of lions?” The king answered, “The statement is true, in accordance with the law of the Medes and Persians, which may not be altered or revoked.”

Then they answered and said before the king, “Daniel, who is one of the exiles from Judah, does not pay any attention to you, O king, or to the injunction which you have signed, but keeps praying [to his God] three times a day.”

Brothers and sisters, I speak in terms of human relations: even though a last will and testament is just a human covenant, yet when it has been signed and made legally binding, no one sets it aside or adds to it [modifying it in some way].