Note to Gamlkan Has 59VII
[5] vest ‘you are’: Normalisation of the ms. reading ‘vertu’ to vest is required if the metre and aðalhending are to be preserved. But compare 14/7 and 61/1, where the r-form is confirmed by the rhyme. The ms., as one would expect, always has r. The change is thought to have taken place in Iceland during the second half of C12th (ANG §§317.4, 498, Anm. 6), and it is likely either that Gamli’s own usage fluctuated between the <s>- and <r>-forms or that he exploited the instability of the phoneme by using an archaic form as and when his rhyme required one.