In a book on the Rule of Saint Benedict that I am currently translating from English into French, I just found this great passage on the Desert Fathers:

In the country around Arsinoe, we saw a certain Serapion, priest
and father of many monasteries: under his care he had more than ten thousand monks, in many and diverse congregations, and all of them earned their bread by the work of their hands, and the great part of what they earned, especially at harvest time, they brought to this father, for the use of the poor.
For it was the custom not only among these, but almost all the Egyptian monks, to hire themselves out at harvest time as harvesters, and each one among them would earn eighty measures of corn, more or less, and offer the greater part of it to the poor, so that not only were the hungry folk of that countryside fed, but ships were sent to Alexandria, laden with corn, to be divided among such as were prisoners in gaols, or as were foreigners in need. For there was not poverty enough in Egypt to consume the fruit of their compassion and their lavishness.

I first found it quoted in Waddell, Desert Fathers, pp. 66–67. Anyway, it’s a great passage I wanted to share.

And then, an attentive reader found the original reference:
Rufinus of Aquileia, Historia Monachorum in Ægypto (trans. Hellen Waddell in The Desert Fathers, [London: Cistercian Publications, 1962]), 17.

He found it in an interesting article, see the link in his comment here below.