"And the LORD smelled" (Genesis 8:21). He smelled the fragrance of Abraham our father rising from the fiery furnace; He smelled the fragrance of Hananiah, Mishael, and Azariah rising from the fiery furnace. A parable of one beloved of a king who honored him with a fine gift on a fine platter. His grandson arose and honored him; he said: this gift of yours resembles the gift of your grandfather. So He smelled the fragrance of those who gave themselves to be killed for the sanctification of the Name.
The Fragrance of Abraham and the Three in the Furnace
Yalkut Shimoni on Torah 60:2
וַיָּרַח ה'. הֵרִיחַ רֵיחוֹ שֶׁל אַבְרָהָם אָבִינוּ עוֹלֶה מִכִּבְשָׁן הָאֵשׁ, הִרִיחַ רֵיחָן שֶׁל חֲנַנְיָה מִישָׁאֵל וַעֲזַרְיָה עוֹלִין מִכִּבְשָׁן הָאֵשׁ, מָשָׁל לְאוֹהֲבוֹ שֶׁל מֶלֶךְ שֶׁכִּבְּדוֹ בְּדוֹרוֹן נָאֶה בְּדִיסְקוּס נָאֶה עָמַד בֶּן בְּנוֹ וְכִבְּדוֹ, אָמַר, דָּמִי דּוֹרוֹן דִּידָךְ לְדוֹרוֹן דְּסָבָךְ כָּךְ הֵרִיחַ רֵיחַ שֶׁל שְׁמָד.