Letters 95.49

And what reason have the gods for doing deeds of kindness? It is their nature. One who thinks that they are unwilling to do harm, is wrong; they cannot do harm. They cannot receive or inflict injury; for doing harm is in the same category as suffering harm. The universal nature, all-glorious and all-beautiful, has rendered incapable of inflicting ill those whom it has removed from the danger of ill.

Seneca, Letters to Lucilius 95.49, translated by Richard Mott Gummere