"For you have left your people" and do not care what happens to them. Here the word "you" refers to Yahweh and so is singular. (See: [[rc://en/ta/man/translate/figs-pronouns]])
Isaiah speaks as if the people were containers who were full of something from the east. Possible meanings are that he speaks of 1) the deeds that the eastern peoples do. Alternate translation: "they do all the time the evil things the people who live in lands east of Israel do" or 2) people, specifically those who claim to speak to dead people, who have come from the east to do evil deeds. Alternate translation: "many diviners have come from the east and now live there" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-explicit]])
Clasping hands together is the symbol of friendship and peace. Alternate translation: "they make peace and work together with people who are not from Israel" (See: [[rc://en/ta/man/translate/translate-symaction]])