31 We seem to see still present before Our eyes the Holy Pontiff Gregory at the Lateran Council, surrounded by a great number of bishops from all parts of the world. Oh, how fruitful is the exhortation that falls from his lips on the duties of the clergy! How his heart is consumed with zeal! His words are as lightnings rending the perverse, as scourges striking the indolent, as flames of divine love gently enfolding the most fervent. Read that wonderful homily of Gregory, Venerable Brethren, and have it read and meditated by your clergy, especially during the annual retreat (Hom. in Evang. i. 17).
Source: Iucunda Sane (Vatican.va)