‘With their flocks and with their herds,
They will go to seek YHWH,
But they will not find him,
He has withdrawn himself from them.'
‘Against YHWH have they dealt treacherously,
Because they have borne strange children.
Now will the new moon devour them,
With their fields (portions).'
When judgment comes on them they will turn to YHWH with an abundance of sacrifices, of both small and large animals. But it will be too late. They will not find Him, because He will already have withdrawn Himself. This will be because they have been unfaithful to YHWH and produced children who are not acceptable to Him. This may either be because their children too were seen as born under the shadow of spiritual whoredom, or because it is referring to the illegitimate children of prostitutes produced in their religious orgies. And the consequence of their ‘illegitimacy' is that they no longer have any ‘right by inheritance' to the land allotted under the covenant.
‘Now will the new moon devour them' may indicate that just as the new moon was a time when animals were devoured in sacrifice, so now Israel/Ephraim also will be devoured. Or it may mean that instead of their new moons being a time of celebration in the future as they look forward to that future, they will rather become a time when they and their fields (their portions allotted by YHWH) will be devoured.