C. F. Keil and Franz Delitzsch on 2 Chronicles 32:30

2Ch 32:30

The same Hezekiah covered the upper outlet of the water Gihon, and brought it down westwards to the city of David, i.e., by a subterranean channel into the city of David (see on 2Ch 32:3). The form ויישׁרם is Piel ויישּׁרם; the Keri is the same conjug., only contracted into ויּשּׁרם, as ויּבּשׁ for וייבּשׁ, the ו of the third person having amalgamated with the first radical, under the influence of the ו consec. With the last clause in 2Ch 32:30 cf. 2Ch 31:21; 1Ch 29:23.