So far we have established that when a man wishes to warn his wife not to consort with a certain man that injunction must be issued in the presence of two competent witnesses. We have also established (in mishnah 2) that the testimony of one witness (and even if that witness was an interested party) would be sufficient to establish a prima facie case for her adultery.
2:
Our present mishnah refers to the testimony that she had been warned as 'the earlier testimony' and the testimony that she had been unfaithful as 'the later testimony'. In the former case, where the husband has no proof of his wife's infidelity he may require her to undertake the test of the 'cursing waters' to satisfy himself of her innocence. In such a case, as we have seen in the 3rd mishnah of Chapter 1, conjugal relations between the husband and wife were forbidden until after she had successfully passed the test, when they would be resumed. This is what our present mishnah means by stating that the earlier testimony does not bar her for ever (but only until after the test). However, the later testimony (that establishes grounds for her divorce) means that conjugal relations between the husband and the wife will never be resumed.
3:
Our mishnah admits that sheer logic would require us to assume the opposite of what has been established. It is logical that a situation in which the consequence is only temporary cessation of conjugal relations must be less stringent than a situation where the cessation would be permanent. Since it is established that 'the former testimony' requires two competent witnesses, it is surely illogical to have a situation in which the more stringent case is established by less stringent testimony! And yet that is exactly the situation that we have established!
To be continued.