Forasmuch as this people refuseth the waters of {g} Shiloah that flow gently, and rejoice in Rezin and Remaliah's son;

(g) Which was a fountain at the foot of mount Zion, out of which ran a small river through the city: meaning, that they of Judah distrusting their own power which was small desired such power and riches as they saw in Syria and Israel.

Wesley's Notes

8:6 This people - The people of Israel, of whom he last spake, who rejoiced not only in their own king, but also in the assistance of so powerful an ally as Rezin. Shiloah - That small brook which ran by Jerusalem. Hereby he understands the munitions and strength of the Jews, which their enemies derided.

Jamieson-Fausset-Brown Bible Commentary

6. waters of Shiloah . softly-Their source is on the southeast of Zion and east of Jerusalem. It means "sent," the water being sent through an aqueduct (Joh 9:7). Figurative for the mild, though now weak, sway of the house of David; in the highest sense Shiloah expresses the benignant sway of Jehovah in the theocracy, administered through David. Contrast to the violent Euphrates, "the river" that typifies Assyria (Isa 8:7; Re 17:15). "This people" refers both to Israel, which preferred an alliance with Rezin of Syria to one with the kings of Judah, and to Judah, a party in which seems to have favored the pretentions of the son of Tabeal against David's line (Isa 7:6); also to Judah's desire to seek an Assyrian alliance is included in the censure (compare Isa 7:17). Isa 8:14 shows that both nations are meant; both alike rejected the divine Shiloah. Not "My people," as elsewhere, when God expresses favor, but "this people" (Isa 6:9).

Matthew Henry's Concise Commentary

8:1-8 The prophet is to write on a large roll, or on a metal tablet, words which meant, Make speed to spoil, hasten to the prey: pointing out that the Assyrian army should come with speed, and make great spoil. Very soon the riches of Damascus and of Samaria, cities then secure and formidable, shall be taken away by the king of Assyria. The prophet pleads with the promised Messiah, who should appear in that land in the fulness of time, and, therefore, as God, would preserve it in the mean time. As a gentle brook is an apt emblem of a mild government, so an overflowing torrent represents a conqueror and tyrant. The invader's success was also described by a bird of prey, stretching its wings over the whole land. Those who reject Christ, will find that what they call liberty is the basest slavery. But no enemy shall pluck the believer out of Emmanuel's hand, or deprive him of his heavenly inheritance.