The promise that God would restore to the people a pure lip recalls
the cleansing of Isaiah’s lips in his famous call passage (Isa. 6:4). Isaiah’s
reference to the uncleanness of his and his people’s lips in that passage is
probably to be understood in the light of his complaint that the people drew
near to God with their mouth and honored him with their lips, but their heart
was far from him (Isa. 29:13); that is, their actions belied their words.
Zephaniah promises a correction of this situation so that all the people can
worship and serve God appropriately. The expression “to call upon Yahweh”
refers specifically to the invoking of God’s name in praise and prayer, but it
is often used as a general expression for worship. The word “serve” can be used
in the sense of cultic service or worship, but it can also be used in the
broader sense of a life of obedience to God’s demands. The phrase “with one
shoulder” is an idiomatic expression derived from the realm of the draft
animals, which were yoked together and with their shoulders shared the weight
of their common work (cf. Isa. 9:3 [4]; 10:27; 14:25). This phrase and the
preceding “all” emphasizes that in the restored Jerusalem, all the people will
serve Yahweh. The oppressive rulers and judges, and the impious prophets and
priests (vs. 3–4), not to mention the servants of Baal and other foreign
deities (Zeph. 1:4–6), will all be gone, and the remnant will all be devoted to
Yahweh (cf. vs. 11–12 below). (J. J. M. Roberts, Nahum, Habakkuk,
and Zephaiah: A Commentary [The Old Testament Library; Louisville, Ky.:
Westminster/John Knox Press, 1991], 217)
