All occurrences of these words are plural. Jesus is speaking to his disciples, but this parable teaches a general truth that applies to all believers. (See: [[rc://en/ta/man/jit/figs-you]])
Here "heart" is a metonym for a person's inner being. The phrase "from your heart" is an idiom that means "sincerely." Alternate translation: "sincerely" or "completely" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-idiom]])