G-d Betrothed Yisrael
Midrash Rabbah - Devarim 3:12
Halachah: When a Jew betroths a woman, who has to pay for the writing of the document of betrothal? Our Rabbis have learnt thus: Documents of betrothal and marriage are written only with the consent of the two parties, and the bridegroom pays the fee.
And this we learn from G-d from His betrothal of Yisrael at Sinai, as it is written, "And Hashem said to Moshe: Go to the people and betroth them to-day and to-morrow" (Shemot 19:10).
And who wrote this document? Moshe.
Where do we know this? For it is said, "And Moshe wrote this law" (Devarim 31:9).
And what reward did G-d give him? A lustrous countenance, as it is written, "That Moshe knew not that the skin of his face sent forth beams" (Shemot 34:29).
To what time does
"While He talked with him" (ib.) refer?
Resh Lakish said: When Moshe wrote the law.