2 Chronicles 30:19

That prepareth his heart to seek God The great thing required in our attendance on God in his ordinances is, that we prepare our hearts to seek him; that the inward man, the spirit, be engaged; that we make heart-work of our religion. All is nothing without this. Hezekiah does not pray that this might be dispensed with, or that the want of other things might be pardoned or overlooked, where this was not. For this is the one thing needful, and God is not, cannot be sought acceptably, without it. But he prays that where this was, other deficiencies and omissions, especially such as were of an external and ritual nature, might be pardoned. Though he be not cleansed according to the purification of the sanctuary With that purification which was required of them that came into God's sanctuary. So he calls it, to distinguish it from that internal purity which they are here acknowledged to have.