וְהָי֤וּ לִמְאוֹרֹת֙ בִּרְקִ֣יעַ הַשָּׁמַ֔יִם לְהָאִ֖יר עַל־הָאָ֑רֶץ וַֽיְהִי־כֵֽן׃
又要在天上的穹蒼中作為發光體，照耀在地上。」事就這樣成了。
Rashi
והיו למאורות AND LET THEM BE FOR LIGHTS — They shall serve also this purpose, namely, to give light to the world.
Ramban
AND THEY SHALL BE FOR LIGHTS IN THE FIRMAMENT OF THE HEAVEN TO GIVE LIGHT UPON THE EARTH. He added here that their light should reach the earth since it is possible for the light to be seen in the heavens and perform all mentioned functions without lighting upon the earth. Hence He said that it be for lights in the firmament of the heaven, directed toward the earth and shining upon it.