There are three independent clauses in this verse. The subject of each clause is Yahweh, but only the third one identifies him. So there is a buildup of tension as readers wonder at first who is the subject of these actions. Good News Translation, New International Version, Revised English Bible, and New Jewish Publication Society’s Tanakh identify Yahweh as the subject immediately. By doing this they seem to lose some of the tension that is intended.
He stretched out his hand over the sea means Yahweh threatened the sea. Since Tyre depended on the sea for its trade, he endangered Tyre’s source of wealth. This same menacing gesture of the outstretched hand occurs in 5.25 (see the comments there; see also 9.12, 17, 21; 10.4; 14.26-27). The sea may be an allusion to Yam, the Canaanite sea god (see Isa 23.4). For this line New Jerusalem Bible translates “He has raised his hand against the sea,” and Bible en français courant says “The Lord has threatened the sea.” Another possibility is “He has shown his power over the sea.”
He has shaken the kingdoms demonstrates Yahweh’s power again, but this time over earthly authorities. The Hebrew verb rendered has shaken may be translated “has caused … to tremble” (Bible en français courant). The Hebrew word for kingdoms a general term for nations (see 14.16). This line may express the result of the previous line, so an alternative model for the two lines is “He stretched out his powerful hand against the sea, causing nations to tremble [with fear]” (similarly New International Version).
The LORD has given command concerning Canaan to destroy its strongholds: There are two problems here. The first one concerns the word Canaan. Canaan includes Phoenicia in this context. The Old Testament rarely does this, so some translations say “Phoenicia” (Good News Translation, New International Version, New Jewish Publication Society’s Tanakh, Die Bibel im heutigen Deutsch), which is in focus here. However, other translations retain the name Canaan (Revised Standard Version, New Revised Standard Version, Revised English Bible, New Jerusalem Bible, New American Bible, Bible en français courant). The Hebrew word for Canaan could mean “merchants” in this context. It comes from the same root as the word for “traders” in verse 8. The second problem in these lines concerns the Hebrew word rendered strongholds. It has an unusual spelling, so there is some question about its exact meaning. De~Waard and other commentators believe it has the same meaning as the Hebrew word translated “stronghold” in verses 4 and 14 since they come from the same root. However, Good News Translation emends it slightly to say “centers of commerce.” Revised English Bible is similar with “marts.” This is a minority view, which is rejected by Hebrew Old Testament Text Project. However, the idea of “markets” fits in well with the overall theme of traders from Tyre and Sidon in this section. A possible model that expresses this for these two lines is “Yahweh has ordered the destruction of the traders’ markets.” Since this rendering reflects a minority view, the third example below, which expresses the majority view, is also valid. No matter what understanding translators follow for this verse, they should add a footnote explaining that the meaning of the Hebrew text here is uncertain.
The verb has given command does not have an indirect object, so we do not know who was ordered to carry out the destruction. If a language requires an indirect object here, translators may say “Yahweh has ordered his agents/representatives to destroy….”
Translation examples for this verse are:
• He has shown his power over the sea, causing nations to tremble;
Yahweh has ordered the destruction of the merchants’ markets.
• He has extended his powerful arm over the sea, he has caused nations to tremble;
it is Yahweh who has given the order that Phoenicia’s markets be destroyed.
• He has extended his hand over the sea, he has made kingdoms afraid,
Yahweh has commanded that Canaan’s fortresses be destroyed.
Quoted with permission from Ogden, Graham S. and Sterk, Jan. A Handbook on Isaiah. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here .