Hosea 10:15

‘So shall Beth-el do to you because of your great wickedness,

At dawn will the king of Israel be utterly cut off.'

The same treatment will be meted out to them by Bethel. In other words, because of their great wickedness carried out at Bethel, Bethel would bring destruction on them, and the king of Israel would be utterly cut off ‘at daybreak/dawn'. The cutting off of the king would usually be the signal of utter defeat. If it refers to Hoshea it was indeed ‘at dawn', prior to ‘the day' of the siege of Samaria, for he went out to meet the king of Assyria before the siege commenced, presumably in order to parley and was arrested as a rebel.

We should note how deeply YHWH felt the wickedness of the people. They were ‘grossly wicked' (Hosea 9:15; Hosea 10:15); ‘guilty' (Hosea 10:2); ‘exceedingly sinful' (Hosea 10:8); ‘wayward' (Hosea 10:9); ‘iniquitous' (Hosea 10:10); ‘wicked' Hosea 10:13; ‘grossly deceitful' (Hosea 10:13). And this has been emphasised by the examples drawn from the past, the sin of Baal-peor (Hosea 9:10); the sin of Gibeah (Hosea 10:9); evil at Gilgal (Hosea 9:15); the sin of Bethel (e.g. the calves of Jeroboam I). All that was bad in the past could also be laid at their door.