Albert Barnes Commentary Jeremiah 35:6-7

"But they said, We will drink no wine; for Jonadab the son of Rechab, our father, commanded us, saying, Ye shall drink no wine, neither ye, nor your sons, for ever: neither shall ye build house, nor sow seed, nor plant vineyard, nor have any; but all your days ye shall dwell in tents; that ye may live many days in the land wherein ye sojourn." — Jeremiah 35:6-7 (ASV)

Wine is the symbol of a settled life, because the vine requires time for its growth and care in its cultivation, while the preparation of the wine itself requires buildings, and it then has to be stored up before it is ready for use. The drink of nomads consists of the milk of their herds (Jeremiah 35:7).

Strangers: This is because they were not of Jewish blood, though wandering in their territory.