From “On the Beginnings of the Order of Preachers” by Jordan of Saxony OP:

Far more impressive and splendid than all his miracles, though, wre the exceptional intergity of his character and the extraordinary energy of divine zeal which carried him along; these proved beyond all doubt that he was a vessel of honour and grace, adorned with every kind of “precious stone”. Hi mind was always steady and calm, except when he was stirred by a feeling of compassion and mercy; and, since a happy heart makes for a cheerful face, the tranquil composure of the inner man was revealed outwardly by the kindliness and cheerfulness of his expression. He never allowed himself to become angry. In every reasonable purpose his mind conceived, in accordance with God’s will, he maintained such constancy that he hardly ever, if ever, consented to change any plan which he had formulated with due deliberation. And though, as has been said, he face was always radiant with a cheerfulness which revealed the good conscience he bore within him, “the light of his face never fell to the ground”. By his cheerfulness he easily won the love of everybody. Without difficulty he found his way into people’s hearts as soon as they saw him.

Wherever he went, whether he was on the road with his companions or in some house, with his host and the rest of the household, or among important people and rulers and prelates, he always overflowed with inspiring words. He had an abundant supply of edifying stories, with which he directed people’s minds to the love of Christ and contempt for the world. Everywhere, in word and in deed, he showed himself to be a man of the gospel. …

It was his very frequent habit to spend the whole night in church, so that he hardly ever seemed to have any fixed bed of his own to sleep in. He used to pray and keep vigil at night to the very limit of what he could force his body to endure. When at last weariness overtook him and his spirit succumbed, so that he had to sleep for a while, he rested briefly before the altar or absolutely anywhere, sometimes even leaning his head against a stone, like the patriarch Jacob. But then he would soon be awake again, rallying his spirit to resume his fervent prayer.

Everybody was enfolded in the wide embrace of his charity, and since he loved everyone, everyone loved him. He made it his business to rejoice with those who were rejoicing and to weep with those who wept. He was full of affection and gave himself utterly to caring for his neighbours and to showing sympathy for the unfortunate.

Another thing which made him so attractive to everybody was his straightforwardness; there was never a hint of guile or duplicity in anything he said of did.