Jeremiah 2:18
And now what hast thou to do in the way of Egypt, to drink the waters of Sihor? or what hast thou to do in the way of Assyria, to drink the waters of the river? And now what hast thou to do in the way of Egypt, to drink the waters of Sihor? or what hast thou to do in the way of Assyria, to drink the waters of the river?
And now what profit is there in going the way of Egypt to drink the waters of Sihor, or going the way of Assyria to drink the waters of the river, instead of trusting the Lord and remaining faithful to Him for help and provision and sustenance. In contrast to those foreign waters, the Lord Himself is the fountain of living water on whom His people were to rely. To turn to those foreign sources is to forsake God and to backslide from Him, an evil and bitter choice.
Their own wickedness and backsliding brings correction and reproof upon them, and the bitter consequences expose their course. That course shows that the fear of the Lord is not in them. In its application to God's people, going to Egypt and Assyria represents forsaking God's Word for human teachings and books that cannot impart spiritual life or truth.
The same warning reaches professed believers who claim to belong to God yet abandon Him for a counterfeit religious allegiance. To uphold the spurious Sabbath in place of God's Sabbath is such a forsaking, and the course leads toward the Roman yoke.