The tenth trial: "And it came to pass after these things that God tested Abraham." Ishmael came out from the wilderness to see Abraham his father. On that very night the Holy One, blessed be He, revealed Himself to him and said to him, "Take now your son."
The Tenth Trial and Ishmael's Visit on the Night of the Command
Yalkut Shimoni on Torah 96:4
הַנִּסָּיוֹן הָעֲשִׂירִי, וַיְּהִי אַחַר הַדְּבָרִים הָאֵלֶה וְהָאֱלֹהִים נִסָּה אֶת אַבְרָהָם. יָצָא יִשְׁמָעֵאל מִן הַמִּדְבָּר לִרְאוֹת אֶת אַבְרָהָם אָבִיו, בְּאוֹתוֹ הַלַּיְלָה נִגְלָה עָלָיו הַקָּדוֹשׁ בָּרוּךְ הוּא וְאָמַר לוֹ, קַח נָא אֶת בִּנְךָ.