Then each wrote his own statement: Nothing is said to indicate the material on which the writing was done. Papyrus may well be the intended writing material. Contemporary English Version has “papers,” which sounds a bit modern, since paper did not exist at that time. But it is certainly a possible translation.

And they sealed them indicates that the writing material was folded in such a way that no one could see the writing without opening the seal. Each message was sealed by putting melted wax over the fold. If the seal was broken, anyone could know that the contents of the message had been read by someone else.

And put them under the pillow of Darius the king: Verse 13 says “When the king awoke, they took the writing and gave it to him, and he read it.” The reader will assume that the pronoun “they” in verse 13 refers to the three bodyguards, but it is more probable that the king’s servants, who made the bed in the morning, are the ones who found the messages under the king’s pillow and gave them to him (see verses 14-16). Putting the messages under the pillow to be found the next day is the way the men devised to let the king know of their contest. Presumably also they must have left some word as to who left the messages and why. (However, as his bodyguards, they were the only ones who could have got that close to him while he slept.) Nothing is said about this, but in 1 Esd 4.42 it is evident that the messages contained suggestions for an appropriate reward.

Good News Bible provides a helpful model for this verse. Another possible model is:

• Then each of them wrote down the best answer he could think of [on papyrus], sealed the message with melted wax, and put it under the king’s [or, emperor’s] pillow.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Esdras. (UBS Helps for Translators). Miami: UBS, 2019. For this and other handbooks for translators see here.