Well, From what Jesus told us, God is a spirit, those who worship him, must do so in spirit and in truth, So When he was teaching us these things, he was referring to how the heart should be, how God wants it to be. (Washing feet- Humility), (selling properties - this is just about giving - according to 2 Corinthians 8:12) the bible is complete, and it cannot contradict itself, so it interprets itself.
About sabbath, just about devoting time to God, Giving your all to God, worshipping him, with your life, 24/7 can be your sabbath, if what you do 24/7 gives glory only to God. Jesus Healed on sabbath day, he was doing the work of our father.. He was WORKING ON SABBATH DAY, Jesus did not break God’s law, but broke the law of those men, because He Perfectly understands God’s commandents, more than those men, what God really wants, so He implemented it. Same reason we were told, whether we eat or drink, do all to the glory of God. Jesus’ teaching here on earth, (According to the bible) should not be seen through the physical perspective, it should be seen as God wants it to be seen. (Though with his spirit) using other scriptures to expound the scriptures that are not too clear, not using our knowledge to try to understand it. This way we can live according to God’s will, to the glory of God..
Besides people who ignore Jesus’ teaching, they might do that, because it offends them, or it interferes with their way of living. Just saying, or maybe they don’t even know that they’re doing so..
The word of God is spirit, it is life. 🥰😘