Gregory the Great
Catena Aurea · Markusevangelium 6
And when the day was now far spent, his disciples came unto him, and said, This is a desert place, and now the time is far passed: Send them away, that they may go into the country round about, and into the villages, and buy themselves bread: for they have nothing to eat. He answered and said unto them, Give ye them to eat. And they say unto him, Shall we go and buy two hundred pennyworth of bread, and give them to eat? He saith unto them, How many loaves have ye? go and see. And when they knew, they say, Five, and two fishes. And he commanded them to make all sit down by companies upon the green grass. And they sat down in ranks, by hundreds, and by fifties. And when he had taken the five loaves and the two fishes, he looked up to heaven, and blessed, and brake the loaves, and gave them to his disciples to set before them; and the two fishes divided he among them all. And they did all eat, and were filled. And they took up twelve baskets full of the fragments, and of the fishes. And they that did eat of the loaves were about five thousand men.
(Mor. 16, 55) The different ranks in which those who ate lie down, mark out the divers churches which make up the one Catholicx. But the Jubilee rest is contained in the mystery of the number fifty, and fifty must be doubled before it reaches up to a hundred. As then the first step is to rest from doing evil, that afterwards the soul may rest more fully from evil thoughts, some lie down in parties of fifty, others of a hundred.