What is the meaning of "Gam b'Lo Da'as Nefesh Lo Tov"?
Rashi: It is not good for a person to be without Torah.
Rashi citing Eruvin 100b: One may not force his wife to have relations. If he does, the children will be improper.
R. Yonah #1: Verse 1 praised Temimus. Here it teaches that even if one is Tamim in his Midos, and he fixed the power that desires from every crooked nature, he must learn Da'as and Chachmah to remove stumbling from his deeds. A Nefesh without Da'as has no importance. Chazal said 1 that one who did not learn Chachmah and Torah will not succeed to fulfill Mitzvos properly. This is like a slave whose master told him to make a cloak, and he never did so before. The master was angry, for it was not good in his eyes. Tamim is one who is complete in his Midos; there is no blemish of lowly Midah in his Nefesh, even if he did not learn Chachmah. Only a Chacham Lev, who understands straightness, can be called Yashar.
R. Yonah #2: It is not good for a man not to know the value of his Nefesh and its understanding of Avodas Hashem. Rather, he must search his ways and constantly investigate. Even if he is complete in his Midos, he must constantly check his deeds - perhaps his intent is acceptable, but his deeds are not. Therefore, he must investigate and know the value of his Nefesh and its understanding and Zerizus in Avodah. He must be careful about what was hidden from him, and fix what he made crooked, and strive to attain what he fell short in it 2 .
Malbim: Even if he does not sin due to Kesilus, only due to lack of Da'as - his Nefesh is without Da'as - this is not good.
Magihah: Tosefta Brachos 6:23 says similarly, and cites Avos (2:5) - a Bur cannot fear sin.
R. Yonah: Iyov said "Tam Ani Lo Eda Nafshi Em'as Chayai" (9:21). I am complete in my Midos, and I ruled over my desires and fixed my power that desires. I know that I will not sin intentionally, and I will not veer from the way of my Sechel to follow my desire. However, I do not know the value of his Nefesh and its understanding. Perhaps due to my small Sechel, and small understanding of my deeds and my Zerizus in Avodah, my sins are many; therefore, this affliction came on me. I know that Hashem's judgments t are "Emes Tzadku Yachdav" (Tehilim 19:10). Therefore, I despise my life, being Tamim in my Midos and my good intent. I do not know my sins to repent from them and go in the path of the straight.
What do we learn from "v'Atz b'Raglayim Chotei"?
Rashi: A sinner tramples sins with his heels, and says 'what I transgress is light.'
Rashi citing Eruvin 100b #1: This is one who has relations and repeats the act 1 .
Rashi citing Eruvin 100b: One may not walk on grass on Shabbos [lest he detach grass 2 ].
R. Yonah: Not only one who did not learn Chachmah sins in deed. Rather, also one who knows Da'as, but he is quick to do what crosses his Ru'ach, without thought and investigation, sins. Man's heart is small, and he often errs. Therefore, one must think before he acts, and contemplate every matter with Binah and deliberation before acting.
Malbim: Also if he rushes with his feet amidst habit, and via this strays from the path, he sins.
100b: One may do so to cause his children to be male, i.e. with his wife's consent. It is forbidden without her consent.
100b: Another Beraisa permits. There are several resolutions. Perhaps we distinguish wet and dry grass (dry is already considered detached), or winter and summer. or one who wears shoes from one who is barefoot (grass between his toes is uprooted), or whether or not his shoes have spikes, or short from long grass. Nowadays we permit, like R. Shimon [who permits Davar she'Eino Miskaven].
