Jamieson, Fausset and Brown on Jeremiah 35:6

6. Jonadab ... our father--that is, forefather and director, three hundred years before (2Ki 10:15). They were called Rechabites, not Jonadabites, having received their name from Rechab the father, previously to their adopting the injunctions of Jonadab his son. This case affords no justification for slavish deference to the religious opinions of the Christian fathers: for Jonadab's injunction only affected matters of the present life; moreover, it was not binding on their consciences, for they deemed it not unlawful to go to Jerusalem in the invasion (Jr 35:11). What is praised here is not the father's injunction, but the obedience of the sons [Calvin].