Love For His Children
There are two aspects of Eis Ratzon [auspicious moments for gaining Hashem's attention]. There is an Eis Ratzon regarding the King's wise and successful son... and there's another aspect of Eis Ratzon when the King has a retarded son who's incapable of doing most anything and one needs to do for him.
Now this latter Eis Ratzon is more powerful than that which the wise son aroused, for it's obvious that he can't succeed with anything! Such was the case at the time of Churban Beis HaMikdash. The situation then was the worst and most degraded it could be... Accordingly, we can understand how, by virtue of tremendous heavenly compassion the Kruvim [Cherubs on top of the Aron] were discovered interlocked with one another.
Thus we learn that Tzaddikim would sublimate every love of theirs except for that for their children – in order to feel this aspect of love that HaKadosh Baruch Hu has for Israel.