And he taught, saying unto them, is it not written ,.... In Isaiah 56:7 .
My house shall be called of all nations, the house of prayer ? For not only the Jews went up to the temple to pray, see Luke 18:10 , but the Gentiles also, who became of the Jewish religion, and had a court built for that purpose; and so the whole temple, from hence, was called an house of prayer: and the meaning is, not only that it should be called so by the Gentiles, but that it should be so to them, and made use of by them as such. Jarchi's note on the clause in Isaiah 56:7 is, "not for Israel only, but also for the proselytes."
But ye have made it a den of thieves ; for no other, in our Lord's esteem, were the buyers and sellers of sheep, oxen, and doves, and the money changers, and the priests that encouraged them, and had a profit out of them: now these had their seats, shops, and tables, within the mountain of the house; and even in that part of it, which was assigned to the Gentiles, the nations of the world, who became proselytes, and came up to Jerusalem to worship there at certain times; See Gill on Matthew 21:13 .