Hilary of Poitiers

(viii. de Trin. ante med) Our Lord therefore hath not left it uncertain whether the Paraclete be from the Father, or from the Son; for He is sent by the Son, and proceedeth from the Father, both these He receiveth from the Son. You ask whether to receive from the Son and to proceed from the Father be the same thing. Certainly, to receive from the Son must be thought one and the same thing with receiving from the Father: for when He says, All things that the Father hath are Mine, therefore said I, that He shall receive of Mine, He sheweth herein that the things are received from Him, because all things which the Father hath are His, but that they are received from the Father also. This unity hath no diversity; nor doth it matter from whom the thing is received; since that which is given by the Father, is counted also as given by the Son.