Sheweth.--Literally, breathes out; perhaps with reference to the cool evening breeze, so welcome in the East. (See Song of Solomon 2:17, Note.) Notice that it is not here the heavens that are telling (as in Psalm 19:1) the tale of God's glory to man, or "to the listening earth," as in Addison's well- known hymn, but day tells its successor day, and night whispers to night, so handing on, as if from parent to son, the great news.
and night untonight showeth knowledge, some understand of the constant and continued succession of day and night; which declares the glory of God, and shows him to be possessed of infinite knowledge and wisdom; and which brings a new accession of knowledge to men; others, of the continual declaration of the glory of God, and of the knowledge of him made by the heavens and the firmament, the ordinances of which always continue; the sun for a light by day, and the moon and stars for a light by night; and so night and day constantly and successively proclaim the glory and wisdom of God: but rather this is to be understood of the constancy of the Gospel ministry, and the continuance of the evangelic revelation. The apostles of Christ persevered in their work, and laboured in the word and doctrine night and day: they were in it at all seasons; yea, were instant in season and out of season; and though they are dead, the Gospel continues, and will do as long as day and night remain: and these, like overflowing fountains, sent forth in great abundance, as the word (x) rendered "uttereth" signifies, the streams of divine light and knowledge; they were full of matter, and their tongues were as the pen of a ready writer; they diffused the savour of the knowledge of Christ, in great plenty, in every place where they came. These words express the continuance of the Gospel revelation, as the next do the extent of it.
(x) "eructat", Musculus, Munster, Vatablus, Junius & Tremellius, Piscator; so Ainsworth; "scaturit", Muis; "scaturiendo effundit", Cocceius; "copiose ac constanter instar foecundae cujusdam scaturiginis protrudit, emittit", Gejerus; so Michaelis.