John Gill Commentary Jeremiah 36:26

"And the king commanded Jerahmeel the king`s son, and Seraiah the son of Azriel, and Shelemiah the son of Abdeel, to take Baruch the scribe and Jeremiah the prophet; but Jehovah hid them." — Jeremiah 36:26 (ASV)

But the king commanded Jerahmeel the son of Hammelech
Or, "the king's son", as the Targum; though it rather seems to be the proper name of a person, one of the king's servants; since it is not probable he would send his own son on such an errand; and had he, he would rather have been called his own son than the king's son; besides, Jeconiah, who succeeded him, seems to be his eldest son, and yet he now could not be more than twelve years of age; whereas this Jerahmeel must be a man grown; and had he been an elder son, as he must, he would have succeeded him, unless it can be thought that he died before his father: and Seraiah the son of Azriel, and Shelemiah the son of Abdeel, to take
Baruch the scribe and Jeremiah the prophet ;
in order to bring them before the king, or to imprison them, or put them to death, for which they might have the king's warrant; the one for prophesying, and the other for writing out and reading his prophecies; though Baruch may be called a scribe, not for being the amanuensis of Jeremiah; but because he was one of the scribes of the law, or doctors of the people:

but the Lord hid them ;
the princes advised them to hide themselves, and they did, very probably in a house of some of their friends; but this would not have been sufficient, had not the Lord took them under his protection; there was no doubt a special providence concerned for them; but by what means this preservation was is not known.

Kimchi suggests that these messengers sought for them in the very place where they were, and could not find them; and conjectures that the Lord set darkness about them, or weakened the visive faculty of those that searched for them, that they could not see them.