This sicha is based off of the possuk "You must not place an obstacle before a blind person" If this instruction were meant to be taken literally, it would be superfluous, since the laws regarding personal damages have already been laid down in parashas Mishpatim. It also cannot only be meant to refer to giving bad advice to someone who is “blind” and unaware or ignorant in a certain area, since that, too, is covered in the prohibition against causing damage. Rather, this verse forbids giving sound advice with ulterior motives. For example, you may not tell a naïve person to sell his field and buy a donkey so that you can then buy his field. Even if this advice is actually advantageous for the “blind” person, it is still prohibited on account of the motivation of the advisor. The Torah is teaching us the proper approach towards helping others. In order to help another yid, we must rid ourselves of any self-oriented motivation, focusing instead solely on the needs of the other person. This gives us a powerful message about Ahavas Yisroel - how far we should go for the well being of a fellow yid. The goal is not only about the other's "good" results, but that in the process, you were doing it only to help him, and not at all with your own agenda. Try to put yourself completely in their place. And only when you do that are you able to avoid subjectivity. When you really feel like your fellow yid is YOU, you have true unity with him, then you will be fully invested in him as if you would be in yourself. As a spouse, parent, shlucha, mechanech, doing chessed for others - remember this mitzvah and put ourselves and our own agenda aside, and not guide someone for our own reason - this is the epitome of v'ahavta lrayacha kamocha.
Chelek Chof Zayin pg 141-148