Charles Ellicott Commentary Jeremiah 32:41

"Yea, I will rejoice over them to do them good, and I will plant them in this land assuredly with my whole heart and with my whole soul." — Jeremiah 32:41 (ASV)

I will plant them in this land assuredly.— Literally, in truth, as in 1 Samuel 12:24, and elsewhere. By some interpreters the words have been referred to the stability of possession implied in the promise, but it is better to see in them an attestation of the faithfulness of the Promiser. In meaning, as in form, the word corresponds closely with the frequent “Amen,” Verily, verily, in our Lord’s teaching.