If Ploni sees that Reuven wants to enter into partnership with Shimon, and Shimon does not know Reuven's nature, and Ploni knows Reuven well from the past — that he is indifferent to the money of others because of his bad nature — he should warn Shimon from the beginning not to enter into partnership with him, and there is no lashon hara in this. But in this, too, he must take great care that none of the conditions mentioned in Principle IX, section 2, are lacking.
אִם הוּא רוֹאֶה, שֶׁרְאוּבֵן רוֹצֶה לְהִשְׁתַּתֵּף עִם שִׁמְעוֹן בְּעִנְיְנִי הַמִּסְחָר, וְשִׁמְעוֹן אֵינוֹ מַכִּירוֹ בְּטִבְעוֹ. וְהוּא מַכִּיר הֵיטֵב לִרְאוּבֵן מִכְּבָר, שֶׁאֵינוֹ חוֹשֵׁשׁ לְמָמוֹן אֲחֵרִים מִפְּנִי טִבְעוֹ הָרַע, יַזְהִיר לָזֶה מִתְּחִלָּה, שֶׁלֹּא יִשְׁתַּתֵּף עִמּוֹ,* וְאֵין בָּזֶה מִשּׁוּם לָשׁוֹן הָרָע. וְגַם בָּזֶה צָרִיךְ לִזָּהֵר מְאֹד, שֶׁלֹּא יַחְסְרוּ בּוֹ כָּל הַפְּרָטִים הַנַּל כְּלָל ט' סָעִיף ב'.
If Ploni sees that Reuven wants to enter into partnership with Shimon, and Shimon does not know Reuven's nature, and Ploni knows Reuven well from the past — that he is indifferent to the money of others because of his bad nature — he should warn Shimon from the beginning not to enter into partnership with him, and there is no lashon hara in this. But in this, too, he must take great care that none of the conditions mentioned in Principle IX, section 2, are lacking.