Saith thus (outw legei). Paul personifies "the from faith righteousness" (h ek pistew dikaiosunh). A free reproduction from Deuteronomy 30:11-14 . Paul takes various phrases from the LXX and uses them for "his inspired conviction and experiences of the gospel" (Denney). He does not quote Moses as saying this or meaning this. Say not in thy heart (mh eiph en th kardiai sou). Second aorist active subjunctive with mh like Deuteronomy 8:17 . To say in the heart is to think ( Matthew 3:9 ). That is, to bring Christ down (tout estin Criston katagagein). Second aorist active infinitive of the common verb katagw, to bring or lead down. It is dependent on the preceding verb anabhsetai (shall ascend). Tout estin (that is) is what is called Midrash or interpretation as in Matthew 9:8 . It occurs three times here (verses Matthew 6-8 ). Paul applies the words of Moses to Christ. There is no need for one to go to heaven to bring Christ down to earth. The Incarnation is already a glorious fact. Today some men scout the idea of the Deity and Incarnation of Christ.