Passage
Day unto day uttereth speech, And night unto night showeth knowledge.
Day unto day uttereth speech, And night unto night showeth knowledge.
Psalms 19:1 The heavens declare the glory of God; And the firmament showeth his handiwork.
Psalms 19:2 Day unto day uttereth speech, And night unto night showeth knowledge.
Psalms 19:3 There is no speech nor language; Their voice is not heard.
Psalms 19:4 Their line is gone out through all the earth, And their words to the end of the world. In them hath he set a tabernacle for the sun,
The verse centers on "uttereth", "speech", "night", "showeth", and "knowledge". It is saying that the verse draws attention to "uttereth" and "speech", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 1's "The heavens declare the glory of God..." into verse 3's "There is no speech nor language Their...", so "uttereth" and "speech" belong inside that flow. In Psalms context, the local focus is worship, trust, the LORD's kingship, and covenant mercy.
A plain takeaway is to answer the verse's own emphasis on "uttereth" and "speech" with trust shaped by these words, not by a vague optimism outside the passage.