The Mekhilta preserves a remarkable story about the descendants of Rechav — also known as the Rechabites, a family that had taken a perpetual vow to drink only water, never wine, and to live a simple, nomadic life in accordance with the command of their ancestor Yonadav ben Rechav (Jeremiah 35:6).
It once happened that one of these "water drinkers" came to the Temple and offered a sacrifice to God. This was a person from a family that had maintained their ancestor's austere vow for generations, never wavering, never compromising, never giving in to the pleasures that the rest of Israel freely enjoyed. And now this faithful descendant stood before the altar with an offering.
At that moment, a Heavenly voice — a bat kol — issued forth from the holy of holies itself. The voice declared: "He who accepted your sacrifices in the desert, He will accept your sacrifices at this time!"
The message was extraordinary. God was drawing a direct line between the wilderness generation and this descendant of Rechav. The same God who had received Israel's offerings in the Sinai desert — in a time of wandering, before the Temple existed, before there was an altar of stone — that same God was now receiving this offering with equal favor. Time had not diminished the covenant. The faithfulness of the Rechabites across the centuries had preserved their standing before God, unbroken from the desert to the Temple.