Gevurot Meyruach Hakodesh 5:38-39

And now I say to you, stay away from these anashim, and leave them alone, because if this cheshbon (plan) or this matter is of Bnei Adam, it will be overthrown. But if it is from HASHEM, you are not able to overthrow them — in that case you may even be found to be fighting keneged (against, opposing) HASHEM. And they were persuaded by Rabban Gamli'el.