2 Chronicles 20:13 Commentary - English Annotations on the Holy Bible by Matthew Poole

Whom they used to present before the Lord in times of great distress, partly to stir up themselves to more fervent and faithful prayers, that their eye, being upon their harmless and tender children, might affect their heart with a greater sense of their misery; and partly to move God to compassion, not as if he were capable of passions or changes upon such a sight, but because God hath declared himself that he will be prevailed with by such methods as these.