Thomas Aquinas

Then when he says but what does, he gives the divine reply, saying: but what does the divine answer say to him, i.e., to Elijah. It is this: I have left me, i.e., for my worship by not permitting them to fall into sin, seven thousand men (this definite number is put in place of the uncertain number, because seven and thousand are perfect numbers), that have not bowed their knees to Baal, i.e., who have not abandoned the worship of God: all who call on my name, whom I created for my glory (Isa 43:17).

Commentary on Romans ↗