Psalms 19:7

and its circuit is to their ends The circuit of its orbit is from one end to the other.

and none is hidden from its heat Had the sun been placed in the lowest sky, no man would be able to hide from its heat (Mid. Ps. 18:13) for the sun and the moon are in the second sky, as is stated (in Hagigah 12b): There are seven skies—Vilon, Rakia, Shehakim, Zevul, Machon, Ma’on, Aravothand he counts them in order: Vilon does not serve for anything; in Rakia are the sun, the moon, the stars, and the planets, etc.

His going forth is from the end of the heaven – i.e. from the east:

And his circuit over the ends of it: – Over all the ends of the heaven is his course. And he says: And his circuit, the interpretation being “his round,” as “the cycle (round) of the year” (Exod. 34:22), because he goes round the (four) quarters and returns to the place of his rising, as Solomon says (Koh. 1:6): “He goeth toward the south and roundeth unto the north” because his course in a day is seen in the south quarter, and he proceeds to the west, and rounds the north quarter at night until he returns in the morning to the quarter from which he rose. And so, in the words of our Rabbis of blessed memory (Babli, 'Erubin 56a), “He proceeds towards the south by day and goes round to the north at night.” This, however, is in appearance only; for his course inclines toward the south side, but does not go to the angle of the south. But according to Astronomy, this is not said of the cycle of the day, but of the year, because he (the sun) inclines southwards in winter and to the north in summer, and this is apparent to the eyes and clear and certain. And so, in the words of our Rabbis of blessed memory, in the Chapters of Rabbi Eliezer (ch. 6): “He goes towards the south in the Tekuphah of Tisri and in the Tekuphah of Tebeth, and goes round to the north at the Tekuphah of Nisan and the Tekuphah of Tammuz.”

And there is nothing hid from the heat thereof: – for it is the same sun in all the world, and that although he is not equally in every place. And he says: And there is nothing hid from the heat thereof, but does not say And there is nothing hid from the light thereof for man is able to hide from (the sun's) light, but not from his heat; even in his innermost chamber (the sun's) heat reaches him. And the learned Rabbi Abraham ben Ezra ex-pounds: And there is nothing hid from the heat thereof “for the sun gives heat in the world just as the heart produces warmth in the body, as Physiology proves; and he is (gives) life to all bodies.” If this is right, the interpretation will be: There is nothing hid from the benefit of his heat.