Nicene and Post-Nicene Fathers, Ser. II, Vol. IV:
Life of Antony. (Vita Antoni.): Section 47

47. And when at last the persecution ceased, and the blessed Bishop Peter 1089 had borne his testimony, Antony departed, and again withdrew to his cell, and was there daily a martyr to his conscience, and contending in the conflicts of faith. And his discipline was much severer, for he was ever fasting, and he had a garment of hair on the inside, while the outside was skin, which he kept until his end. And he neither bathed his body with water to free himself from filth, nor did he ever wash his feet, nor even endure so much as to put them into water, unless compelled by necessity. Nor did any one even see him unclothed, nor his body naked at all, except after his death, when he was buried.

Footnotes

Martyred on Nov. 25, 311, cf. Eus. H. E. vii. 32.