It seems to me that Israel in this chapter is being called on the carpet. They have forgotten that they have the most high God as their Lord and Master. They have been provided for, set apart and it has been revealed to them. So they are a knowledgeable, blessed people that the Creator of all things has set aside, saying "these are mine". But poor Israel has a lateral view. They stopped even looking up. God says that they don't even consider what the the ox and donkey know.
As Christians today, I would say for myself, I too have seasons of forgetfulness, but God forbid that I walk long that way. I would spend days, just as any other Christian,with wasted moments serving idols, and marking days, and my borders would be just as weak as Israel's here in Isaiah. Weakened borders around my family, spiritual walk and the work that God has called me to.
God accuses Israel of all sorts of things, but the thing that most stands out to me is this statement, "bring no more futile sacrifices, in vs. 13 of Chapter 1. In vs. 11 it is said " To what purpose is the multitude of your sacrifices to Me?"... "I do not delight in the blood of bulls, or of the lambs or goats." It is something that I needed to hear again, and it said to me, "where is your heart, Cat? These things were so that you would look at your heart in alignment with Me and My Heart". Oh yeah! It is unreasonable for me with so much at my disposal,(grace, mercy, a direct line to the Creator of all things) to rely on ordinances, pass times in place of worship, and miss the garden of that grace that is available to me.
Wash yourselves, make yourselves clean; Put away the evil of your doings from before My eyes. Cease to do evil, Learn to do good; Seek justice, Rebuke the oppressor, Defend the fatherless, Plead for the widow.