Bellarmine on Psalm XVIII: Verses 6-7

 Verses 6 & 7

(He) hath rejoiced as a giant to run the way: His going out is from the end of heaven, And his circuit even to the end thereof: and there is no one that can hide himself from his heat.

Exsultavit ut gigas ad currendam viam; a summo caelo egressio ejus. Et occursus ejus usque ad summum ejus; nec est qui se abscondat a calore ejus. 

He draws another reason from the strength and power with which the sun tirelessly performs an almost immeasurable journey at huge speed. “He hath rejoiced as a giant,” or as a mighty and sturdy one, (as the Hebrew is read), “to run the way.” Rejoicing suggests alacrity, which they have who do something effortlessly and with great desire. It means here that the mighty sun accomplishes its high-speed trajectory across the space of the heavens without the slightest fatigue. “His going out is from the end of heaven, And his circuit even to the end thereof.” By summum cœlum / the end of heaven is meant the East. In this text summum does not mean the height but the extremity, as the Hebrew kets and the Greek show.  called The word extremum / extremity means where a thing begins, and where it ends. But the heavens begin in the East because it is from thence that their movement begins, and it is there where the movement finishes. The sense is therefore that the sun rises in the East and, having coursed its way across to the West, it returns to the East.  It matters little that in Hebrew and Greek the verb is in the future, exultabit / He will rejoice, where we have exultavit / He hath rejoiced. For the future tense is often put for the praeterite. And so St. Jerome translates it as exultavit / He hath rejoiced; and it is also read this way in St. Augustine’s Commentary. “And there is no one that can hide himself from his heat.” This is the last reason put forward, based upon the benefits which all those receive who are beneath the sun; for the sun indeed warms all by his life-giving heat, so that he may be said to be the common father of all things born or hatched on earth or in the sea. And here is the reason why the sun so assiduously and carefully orbits the earth, visiting all — so that not a single thing may be hidden, that is, excluded from partaking of such signal favour. 

Totus tuus ego sum

Et omnia mea tua sunt;

Tecum semper tutus sum:

Ad Jesum per Mariam.