One Who Helps Others Helps Himself:
Rav Yitzchok of Vorka zy”a asks why it says to pick up “with him” (imo), rather than saying to “pick him up” (oso). He further asks why the Torah says a repetitive “double lashon” of “hakim takim”.
He answers that the word is repeated to teach us that if you pick up and support your friend, you will also be picking up yourself, as Chazal say (Bava Kama 92A): “If one asks for mercy for his friend... he is answered first.” Thus, one is picking himself up “with him.”
In a similar vein, the Sefas Emes explains that when one helps his friend, he rectifies himself and improves his own character. Thus, the pasuk is saying that if one lifts up his friend in order to assist him, he lifts up his moral character “with him.” This is in accordance to Chazal’s statement (Vayikroh Rabbah 34:10) that “a poor man does more for a householder than the householder does for the poor man.”
We see that whenever someone does a favor for someone else, he gains more from it than the recipient of the favor. The opposite is also true. When one hurts someone else, he hurts himself even more.
