Another interpretation: a parable of a king who had a poor friend. The king said to him, "It is upon me to make you rich," and he gave him money in order to conduct business with it. In time he entered the palace. They said, "Why does this one enter?" The king said to them, "Because he is my faithful friend." They said to him, "If so, tell him to return your money." Immediately the king said to him, "Return to me what I gave you," and he did not hold back, and the members of the palace were put to shame; and the king swore to add to his wealth. The Holy One, blessed be He, said to the ministering angels: Had I listened to you when you said to Me, "What is man that You are mindful of him?" (Psalms 8:5), would there have been an Abraham who glorifies Me in My world? The attribute of justice said before the Holy One, blessed be He: All the trials with which You tested him were with his wealth; test him with his body. They said: Let him offer up his son before You. Immediately He said to him, "Take now your son."
The King and His Poor Friend Tested Before the Royal Court
Yalkut Shimoni on Torah 96:3
דָּבָר אַחֵר, לְמֶלֶךְ שֶׁהָיָה לוֹ אוֹהֵב עָנִי. אָמַר לוֹ הַמֶּלֶךְ, עָלַי לְהַעֲשִׁירְךָ, וְנָתַן לוֹ מָמוֹן כְּדֵי לַעֲשׂוֹת בּוֹ פְּרַקְמַטְיָא. לְיָמִים נִכְנַס לְפַּלְטִין. אָמְרוּ, מִפְּנֵי מַה זֶה נִכְנַס, אָמַר לָהֶם הַמֶּלֶךְ, מִפְּנֵי שֶׁהוּא אוֹהֲבִי נֶאֱמָן. אָמְרוּ לוֹ, אִם כֵּן, אֱמוֹר לוֹ שֶׁיַּחְזֹר מָמוֹנְךָ. מִיַּד אָמַר לוֹ הַמֶּלֶךְ, הַחְזֵר לִי מַה שֶׁנָּתַתִּי לְךָ וְלֹא עִכֵּב וְנִתְבַּיְּשׁוּ בְּנֵי הַפְּלָטִין וְנִשְׁבַּע הַמֶּלֶךְ לְהוֹסִיף לוֹ עֹשֶׁר. אָמַר הַקָּדוֹשׁ בָּרוּךְ הוּא לְמַלְאֲכֵי הַשָּׁרֵת אִלּוּ שָׁמַעְתִּי לָכֶם כְּשֶׁאָמַרְתֶּם לִי "מָה אֱנוֹשׁ כִּי תִזְכְּרֶנוּ", שֶׁמָּא הָיָה אַבְרָהָם שֶׁמְּהַדְרֵנִי בְּעוֹלָמִי, אָמְרָה מִדַּת הַדִּין לִפְנֵי הַקָּדוֹשׁ בָּרוּךְ הוּא, כָּל הַנִּסְיוֹנוֹת שֶׁנִּסִיתוֹ בְּמָמוֹנוֹ, נַסֶּנוּ בְּגוּפוֹ אָמְרוּ לוֹ יַקְרִיב לְפָנֶיךָ בְּנוֹ, מִיַּד אָמַר לוֹ קַח נָא אֶת בִּנְךָ.