Ignatius was about to enter on a life of renunciation and penance, and, being a beginner, stood in need of preparation and armour. He therefore entered the chapel of Our Lady at Montserrat—it was on the 24th of March, the vigil of the Annunciation, 1522— and spent a whole night in keeping his spiritual "vigil in arms." Those who have most carefully collected his own statements affirm positively, on his authority, that he drew his inspirations from the old customs of chivalry, nay, that he was acting from recollection of the accounts of "Amadis" and other writings of the same kind. But his armour was no longer the same. He had hung up in the chapel his baldric, dagger and sword. His spiritual armour consisted of the clothes of a poor man, for which he had exchanged his own, a kind of gown of coarse cloth, shoes of esparto-grass, a rope girdle, a gourd, and a sort of wallet, destined to carry, together with his bread, the book which he had taken away from Loyola—probably the volume composed by himself of all sorts of extracts from pious works.
Link (here) to the mentioned portion of the book entitled, St. Ignatius of Loyola by Jesuit Fathers Henri Joly, George Tyrrell