Who blesses whom?
Rashi: The Rasha blesses his Nefesh in his lifetime, and says that it will have Shalom; nothing bad will happen to him. Others do not say so about him!
Radak: The Rasha should have blessed his Nefesh in his lifetime. He should not have made his only venture to benefit his body. He should have benefited his Nefesh, with Chachmah and good deeds! "Yevarech" refers to extra good; he should give so to his Nefesh, but to his body, only what is needed to live.
Malbim: One who wants his acquisitions to be his, he must spend them for needs of his Neshamah, and bless his Nefesh, and not his body.
What is the meaning of "v'Yoducha Ki Seitiv Lach"?
Rashi: If you will heed my words, all will admit that you benefit your Nefesh to straighten your path.
Radak: This addresses one who is wise. If you will do so, the wise will admit that you benefit yourself.
Malbim: They will admit to you if you benefit yourself, i.e. your Neshamah, but not if you benefit strangers who will inherit your wealth.
