Adam Clarke on Isaiah 54:9

For this is as the waters of Noah unto me "The same will I do now, as in the days of Noah" - כימי kimey, in one word, in a MS., and some editions; and so the Syriac, Chaldee, Vulgate, Symmachus, Theodotion, Abarbanel, Sal. ben Melec, and Kimchi acknowledge that their copies vary in this place.

It is certain that these two words כי מי ki mey, were written formerly as one. Taken as two כי מי ki mey, they signify for as the waters - when as one, כימי kimey, they signify as the days. This latter reading is found in about four of Kennicott's and De Rossi's MSS. In one of my own it appears to have been intended as one word: but he who added the points, which are by a much later hand than the MS. itself, has pointed the letters so as to make the two words which are commonly found in the text. For the waters, Symmachus, Theodotion, the Syriac, Vulgate, and Arabic have days. The former seems to make the best sense; and the ancient Versions, except the Septuagint, support it.