Jeremiah 35:19

35:19 So the Lord God of Israel who rules over all says, ‘Jonadab son of Rechab will never lack a male descendant to serve me.’” ¹ 

[35:19]  ¹ tn Heb “There shall not be cut to Jonadab son of Rechab a man standing before me all the days.” For the first part of this idiom see 33:17-18 where it is applied to David always having a descendant to occupy the throne and the Levites will always have priests to offer up sacrifices. For the latter part of the idiom “to stand before” referring to service see BDB 764 s.v. עָמַד 1.e and compare the usage in 1 Kgs 1:2; 2 Kgs 3:14; Jer 15:19; Deut 10:8. As comparison with those passages will show, it refers to attending on, or serving a superior, a king, or the Lord. It is used of both prophets (e.g., 1 Kgs 17:1) and priests (e.g., Deut 10:8) serving the Lord. Its most common use is to refer to priestly service. The nature of the service is not further defined in this case, though several of the commentaries point out a Mishnaic tradition that the Rechabites later were given the function of bringing wood for the altar.