The Posuk says(47:29):
וְעָשִׂיתָ עִמָּדִי חֶסֶד וֶאֱמֶת
Translated as do with me Kindness and truth Rashi is bothered that Chesed and Emes are two different things so Rashi says:
חסד ואמת: חסד שעושין עם המתים הוא חסד של אמת, שאינו מצפה לתשלום גמול
Translated as: Kindness done with the dead as you know you can not pay back
The question is in Parshas Chayei Sarah(24:49) it uses the term
וְעַתָּה אִם-יֶשְׁכֶם עֹשִׂים חֶסֶד וֶאֱמֶת, אֶת-אֲדֹנִי--הַגִּידוּ לִי
and it is not for the dead,this is not Chesed Shel Emes. This was Chesed V’emes. So it is difficult to understand what bothered Rashi in our Parsha when we find this expression mentioned elsewhere?