What will ye do in the solemn day, and in the day of the feast of the Lord?] Since their sacrifices now were so disagreeable and displeasing to the Lord, and so unavailable to themselves, what would they do when in captivity, "in the solemn day", the seventh day of the week, appointed by the Lord for rest and religious worship; and in the first day of the month, which also was to be solemnly observed, by offering sacrifice, &c.
and on feast days of the Lord's instituting, as the feasts of the passover, pentecost; and tabernacles? seeing those that carried and held them captive would not allow them time for such solemnities; nor would they be furnished with proper sacrifices; nor could they be accommodated with a proper place to offer them at; nor be able, in a strange land, and under hardships and miseries, to express that joy that is suitable to such occasions: thus should they learn, by sad experience, the want of those means and opportunities of serving the Lord, which in their own land they rejected and despised.
Jarchi and Kimchi interpret this of the destruction of Israel, and of punishment inflicted on them at the time appointed by the Lord; and which would be a solemn time, a feast with the Lord, to which he should invite their enemies, and they should spill their blood as the blood of sacrifices; and when he would display the glory of his justice, truth, and faithfulness, before all the world.
And it is asked, what will you do then? whither will you flee for help? or what sacrifice can you offer up to the Lord to atone for sin, or appease his wrath? will you be able to rejoice then?