Pope Pius XII
Mystici Corporis Christi §97
Mystici Corporis Christi: On the Mystical Body of Christ
97 In this gravest of hours, Venerable Brethren, when bodies are racked with pain and souls are oppressed with grief, every individual must be aroused to this supernatural charity so that, by the combined efforts of all good men, striving to outdo each other in pity and mercy - We have in mind especially, those who are engaged in any kind of relief work - the immense needs of mankind, both spiritual and corporal, may be alleviated, and the devoted generosity, the inexhaustible fruitfulness of the Mystical Body of Jesus Christ, may shine resplendently throughout the whole world.
Source: Mystici Corporis Christi (Vatican.va)