Sifrei Bamidbar 41

(Bamidbar 6:25) "The L-rd cause His countenance to shine upon you": He will give you "light" of the eyes. R. Nathan says: This refers to the light of the Shechinah, as it is written (Isaiah 60:1-2) "Arise, shine, for your Light has come. For the darkness will cover the earth, and a thick mist, the peoples, but upon you the L-rd will shine, and His glory will be seen upon you," (Psalms 67:2) "G-d will favor us and bless us. He will cause His countenance to shine upon us, Selah," (Ibid. 118:27) "… and He shone for us." Variantly: "The L-rd cause His countenance to shine upon you": This refers to the light of Torah, as it is written (Proverbs 6:23) "For a mitzvah is a lamp, and the Torah, light." "and be gracious to you": in (the granting of) your requests, as it is written (Shemot 33:19) "And I shall be gracious to whom I shall be gracious, and I shall be merciful to whom I shall be merciful." Variantly: Let Him grant you grace in the eyes of man, as it is written (Bereshit 39:21) "And He granted him grace in the eyes of the overseer of the prison," and (Esther 2:14) "And Esther found favor in the eyes of all who saw her," and (Daniel 1:9) "And G-d granted Daniel grace and mercy," and (Proverbs 3:4) "You will find favor and goodly wisdom in the eyes of G-d and man." Variantly: "and be gracious to you": with understanding, insight, mussar, and wisdom. Variantly: "and be gracious to you": in Torah study, as it is written (Proverbs 4:9) "It (Torah) will set a chaplet of grace upon your head," and (Ibid. 1:9) "For they (words of Torah) are a chaplet of grace to your head and a necklace to your throat." Variantly: "and be gracious to you": with gifts of "grace," as it is written (Psalms 123:2) "Behold, as the eyes of servants to their masters; as the eyes of a maidservant to the hand of her mistress, so are our eyes to the L-rd our G-d, until He grants us grace," and (Ibid. 3) "Grant us grace, O L-rd, grant us grace, for we are fully sated with contempt, and (Isaiah 33:2) "O L-rd, grant us grace, for in You have we hoped."