Albert Barnes Commentary Jeremiah 11:19

"But I was like a gentle lamb that is led to the slaughter; and I knew not that they had devised devices against me, [saying], Let us destroy the tree with the fruit thereof, and let us cut him off from the land of the living, that his name may be no more remembered." — Jeremiah 11:19 (ASV)

Like a lamb or an ox - Rather, “like a tame lamb.” Jeremiah had lived at Anathoth as one of the family, never suspecting that, like a tame lamb, the time would come for him to be killed.

The tree with its fruit - The words are those of a proverb or dark saying. All the Churches agree in understanding that under the person of Jeremiah these things are said by Christ.