Cap. III Sol. Rat. 5: Thomas and Augustine — electing makes worthy; holy not foreseen
Thomas notes: we must say God loves some more than others — for God's love is the cause of things' goodness, and nothing would be better than another if he did not will a greater good to one than to another (ST I q.20 a.3). On Romans 9: election does not look to a good already in the person but makes it. He learned that from Augustine (Contra Jul. Pelag. 5.3): God did not elect those he foresaw as worthy, but by electing made them worthy. Both drew it from the Apostle: God elected us that we should be holy — not because we were foreseen holy.
Latin
Hoc Thomas annotavit, Necesse est dicere quod Deus quosdam aliis magis amet. Nam cum amor Dei sit causa bonitatis rerum, non esset aliquid alio melius, si Deus non vellet uni majus bonum quam alteri. Part. I. qu. 20. art. 3. Et in commentariis ad Rom. cap. 9. Electio non respicit bonum in homine, sed facit. Quod ab Augustino didicit, qui contra Jul. Pelag. lib. 5. cap. 3. docet, Deum non elegisse quos praevidit dignos, sed eligendo effecisse dignos. Uterque hanc doctrinam hausit ab Apostolo, qui dicit, Deum elegisse nos ut sancti essemus; non quia sancti praevisi fuimus.