What is the meaning of "va'Yo'el Laleches"?
Rashi citing Targum Yonasan: V'Lo Ava Lemeizal (he did not want to go, i.e. in them. Even though Yo'el means to want,) there are words that have opposite meanings, e.g. "Mesa'ef Purah" (Yeshayah 10:33 - to cut off Sa'ifim (branches), "v'Shereshcha me'Eretz Chayim" (Tehilim 52:7; you will be uprooted, even though Shoresh means root).
Rashi, Malbim: He wanted to go in them and try them, but he saw that they are heavy on him, so he removed them.
What is the meaning of "Ki Lo Nisah"?
Rashi citing Targum Yonasan: Arei Lo Alif (he am not used to them).
Malbim: He never tried them (therefore he thought that he can go in them).
What is the meaning of "Ki Lo Nisisi"?
Rashi citing Targum Yonasan: Arei Leis Behon Nisa (there is no miracle in them). Radak - i.e. the miracle Hashem will do for me will not be recognized if I go with war Kelim. This is a Drashah; one should not uproot the words from the simple meaning (refer to 17:39:3:2).
Radak: I am not used to them. Vayikra Rabah 26:9 - David saw that Sha'ul's face whitened, therefore he said "Ki Lo Nisisi" and removed them. (I.e. he could have gone in them, just he did not want to arouse Sha'ul's envy. - PF)
