Hilary of Poitiers
Catena Aurea · Johannesevangelium 14
Philip saith unto him, Lord, shew us the Father, and it sufficeth us. Jesus saith unto him, Have I been so long time with you, and yet hast thou not known me, Philip? he that hath seen me hath seen the Father; and how sayest thou then, Shew us the Father? Believest thou not that I am in the Father, and the Father in me? the words that I speak unto you I speak not of myself: but the Father that dwelleth in me, he doeth the works. Believe me that I am in the Father, and the Father in me: or else believe me for the very works’ sake.
(vii. de Trin) That the Father dwells in the Son, shews that He is not single, or solitary; that the Father works by the Son, shews that He is not different or alien. As He is not solitary who doth not speak from Himself, so neither is He alien and separable who speaketh by Him. Having shewn then that the Father spoke and worked in Him, He formally states this union: Believe Me that I am in the Father, and the Father in Me: that they might not think that the Father worketh and speaketh in the Son as by a mere agent or instrument, not by the unity of nature implied in His Divine birth.