This reading is from the special Torah portion read on the Shabbat during Passover, Parshat Pesach, Exodus 33:12-34:26.
Moses said to the Lord, "See, You say to me, 'Lead this people forward,' but You have not made known to me whom You will send with me. Further, You have said, 'I have singled you out by name, and you have, indeed, gained My favor.' Now, if I have truly gained Your favor, pray let me know Your ways, that I may know You and continue in Your favor. Consider, too, that this nation is Your people."
And He said, "I will go in the lead and will lighten your burden." And he said to Him, "Unless You go in the lead, do not make us leave this place. For how shall it be known that Your people have gained Your favor unless You go with us, so that we may be distinguished, Your people and I, from every people on the face of the earth?"