Vasquez: a decree to concur is understood under the condition, but God has decreed nothing about that case
Gabriel Vasquez makes this point in his commentary on the first part of Thomas. 'Nevertheless,' he says, 'we must say that God knows future things under a condition with certainty in such a way that his decree to concur with the will is also understood within the condition. It runs like this. God knew well: "If on this or that occasion I gave Peter this or that call, and cooperated with it as it required, and did not miraculously withdraw my concurrence, such a deed would be done. Yet I could withdraw it if I pleased." But whether God would deny or grant his concurrence in that case, he himself decreed nothing.' Volume 1, disputation 67, chapter 4.
Latin
V. Id observat Gabriel Vasquez in primam partem Thomae, Nihilominus, inquit, dicendum est ita Deum certo cognoscere futura sub conditione, ut etiam sub conditione subintelligatur Dei decretum de concurrendo cum arbitrio, hoc modo, Deus bene novit, si Petro in hac occasione, vel illa, darem hanc, vel illam vocationem, & ego cum illa cooperarer, secundum quod illa postularet, nec miraculose subtraherem concursum meum, fieret tale opus: possem tamen subtrahere, si placeret: utrum autem Deus esset negaturus concursum, an concessurus, in eo casu nihil decrevit ipse. Tom. 1. disput. 67. cap. 4.