John of Damascus — on Gal 2:4

“The preposition 'because of' (dia) was put here instead of 'according to' (kata). But the sense is this. The Apostles, he says, did not force Titus, who was uncircumcised, to be circumcised, although this was pointed out by the brethren who were brought in secretly and pressed for circumcision. Indeed he put them in the place of spies because of what is foreign to the truth.”