he shall roar like a lion - by awful judgments on their foes (Isa 31:4; Jer 25:26-30; Joe 3:16), calling His dispersed “children” from the various lands of their dispersion.
shall tremble - shall flock in eager agitation of haste.
from the west - (Zec 8:7). Literally, “the sea.” Probably the Mediterranean, including its “isles of the sea,” and maritime coast. Thus as Hos 11:11 specifies regions of Africa and Asia, so here Europe. Isa 11:11-16, is parallel, referring to the very same regions. On “children,” see Hos 1:10.