They grant conditional predictions (Keilah) but make them follow a decree to permit and predetermine (Alvarez)
They do not deny that some things that would happen contingently and freely under a condition are foreknown by God with certainty and foretold in Scripture. God foretold to David that if he stayed in Keilah, Saul would come to seize him, and that if Saul came to that city, its inhabitants would hand David over to him.
But they insist that this certain foreknowledge of God follows a free decree in God, by which he determined that this or that should happen if this or that condition were fulfilled. Thus God foreknew that if David stayed in Keilah, Saul would come and the people of Keilah would hand David over. He foreknew it because, given that condition, he had decreed both to permit those acts and to predetermine to their substance the wills of Saul and of the inhabitants of Keilah.
This can be seen at greater length in Didacus Alvarez, On the Aids of Divine Grace, book 1, chapter 6, titled 'That besides merely natural and merely free knowledge, no middle knowledge is to be posited, even in God.' See also the next chapter, where he answers the objections of the teachers who hold the opposite view.
Latin
XXI. Itaque non negant quidem quaedam contingenter & libere futura sub aliqua conditione a Deo certo praesciri, & in Scriptura praedici, quemadmodum Deus Davidi praedixit, quod si in urbe Kehila maneret Saul, venturus erat ad ipsum prehendendum; & rursus quod, si Saul ad urbem illam veniret, incolae erant ipsum in manus Saul tradituri: Sed pertendunt certam illam Dei praescientiam sequi liberum in Deo decretum, quo statuerit ut haec aut illa fiant, si adimpleatur haec vel illa conditio. Exempli causa, Deum praescivisse quod David manente in urbe Kehila, Saul venturus esset, & Kehilani essent Davidem tradituri, quia, posita illa conditione, Deus decreverat utrumque permittere, & ad substantiam illorum actuum voluntatem Saulis, & incolarum urbis Kehila praedeterminare. Prout latius videre est apud Didacum Alvarez de Auxiliis divinae gratiae lib. 1. cap. 6. cujus Titulus est, Quod praeter scientiam mere naturalem, & mere liberam, nulla sit, etiam in Deo, scientia media constituenda. Et sequenti quoque capite, in quo Doctorum diversae sententiae objectiones dissolvit.