"And He said, You cannot see My face" (Exodus 33:20). The Holy One, blessed be He, said to Moses: When I wanted you to see, you did not want to; and now that you want, I do not want. But this disagrees with what Rabbi Shmuel bar Nachmani said in the name of Rabbi Yonatan: As a reward for three things he merited three things. As a reward for "And Moses hid his face" (Exodus 3:6) he merited a radiant countenance. As a reward for "because he was afraid" (Exodus 3:6) he merited "and they were afraid to come near him" (Exodus 34:30). As a reward for "from looking" (Exodus 3:6) he merited "and he beholds the form of the LORD" (Numbers 12:8). "And I will remove My hand, and you shall see My back" (Exodus 33:23). This teaches that the Holy One, blessed be He, showed him the knot of the tefillin.
When I Wanted, You Refused, and the Knot of the Tefillin
Yalkut Shimoni on Torah 396:1
וַיֹּאמֶר לֹא תוּכַל לִרְאֹת אֶת פָּנָי. אָמַר לֵיהּ הַקָּדוֹשׁ בָּרוּךְ הוּא לְמֹשֶׁה. כְּשֶׁרָצִיתִי, לֹא רָצִיתָ, וְעַכְשָׁיו אַתָּה רוֹצֶה, אֵין אֲנִי רוֹצֶה. וּפְלִיגָא דְּרַבִּי שְׁמוּאֵל בַּר נַחְמָנִי אֲמַר רַבִּי יוֹנָתָן. בִּשְׂכַר שָׁלֹשׁ זָכָה לְשָׁלֹשׁ. בִּשְׂכַר "וַיַּסְתֵּר מֹשֶׁה פָּנָיו" זָכָה לִקְלַסְתֵּר פָּנִים. בִּשְׂכַר (שם) "כִּי יָרֵא" זָכָה "וַיִּירְאוּ מִגֶּשֶׁת אֵלָיו". בִּשְׂכַר (שמות ג, ו) "מֵהַבִּיט", (במדבר יב, ח) "וּתְמֻנַת ה' יַבִּיט". וַהֲסִרֹתִי אֶת כַּפִּי וְרָאִיתָ אֶת אֲחֹרָי. מְלַמֵּד שֶׁהֶרְאָה לוֹ הַקָּדוֹשׁ בָּרוּךְ הוּא קֶשֶׁר שֶׁל תְּפִלִּין.