קטורה. זוֹ הָגָר, וְנִקְרֵאת קְטוּרָה עַל שֶׁנָּאִים מַעֲשֶׁיהָ כִּקְטֹרֶת (בראשית רבה), וְשֶׁקָּשְׁרָה פִּתְחָהּ, שֶֶׁלֹא נִזְדַּוְּגָה לְאָדָם מִיּוֹם שֶׁפֵּרְשָׁה מֵאַבְרָהָם:
קטורה KETURAH — This is Hagar. She was named Keturah because her deeds were as beautiful (sweet) as incense (Ketoreth) (Genesis Rabbah 61). And since she closed her 'opening,' as she did not mate with anyone from the time she separated from Avraham (Genesis Rabbah 61:4).