Halakhah for Pirkei Avot 1:7
נִתַּאי הָאַרְבֵּלִי אוֹמֵר, הַרְחֵק מִשָּׁכֵן רָע, וְאַל תִּתְחַבֵּר לָרָשָׁע, וְאַל תִּתְיָאֵשׁ מִן הַפֻּרְעָנוּת:
Nittai Ha'arbeli says: Distance yourself from an evil neighbor, [so that you not learn from his deeds, and, also, so that you not share in his downfall, for "Woe to the wicked and woe to his neighbor!"], and do not befriend the wicked one. [For thus did the sages say: All who attach themselves to the wicked, even though they do not emulate them, receive recompense as they do. To what may this be compared? To one's entering a spice shop. Even if he takes nothing, he absorbs the aroma and it leaves with him], and do not "despair" of [the arrival of] punishment [i.e., do not say: "I shall cleave to this wicked one, whose deeds are prospering, for fortune is favoring him." He, therefore, says: "Do not despair of punishment." That is, know that punishment will quickly come upon him, his undoing overtaking him of a sudden.]