A harsh rebuke is directed toward a generation deeply entrenched in idolatry, acting with extreme arrogance before the Divine presence. Historically, this warning was likely delivered near the end of Isaiah's life, during the early years of King Manasseh's reign, when the nation reverted to idol worship. Because the prophet was elderly and unable to rebuke the people in public, he wove the specific sins of his generation into his broader visions of the end of days, effectively addressing his contemporaries [שד״ל].
The people's behavior is characterized by a shocking level of disrespect. The primary approach among commentators is that this represents open defiance, much like a servant who disobeys his master while the master is watching him directly [אבן עזרא]. Others explain this arrogance geographically: the sins are committed in Jerusalem and even within the Temple itself. Because this is the resting place of the Divine Presence, their actions are considered as being done right in front of God [רד״ק, מצודת דוד]. A contrasting perspective views this as a critique of hypocrisy. In this view, the people put on a public show of fearing God but commit their sins in secret, where only He can see them. They anger God directly by ignoring His providence, behaving as though their actions are safely hidden from human eyes while completely disregarding that He is watching [מלבי״ם].
The specific methods of their worship further highlight their corruption. They adopted the practice of setting up idols within private gardens and offering sacrifices to them there. These gardens functioned as small, dedicated groves or forests for ritual use, echoing the ancient pagan custom of worshipping under every leafy tree [רד״ק, שד״ל, מצודת דוד].
Additionally, their rituals involved burning incense on bricks, which were blocks of clay fired in a kiln for construction [מצודת ציון]. They would place spices directly on these bricks to offer incense to their false gods [רש״י]. Some note that the specific custom was to place the incense on the bricks at the exact moment they were being fired in the kiln [רד״ק, מצודת דוד]. However, others acknowledge that the precise details of this ancient pagan ritual remain unknown today [שד״ל].