Pope Pius XII
Divino Afflante Spiritu §27
Divino Afflante Spiritu: On Promoting Biblical Studies
27 Let Catholic exegetes then disclose and expound this spiritual significance, intended and ordained by God, with that care which the dignity of the divine word demands; but let them scrupulously refrain from proposing as the genuine meaning of Sacred Scripture other figurative senses. It may indeed be useful, especially in preaching, to illustrate, and present the matters of faith and morals by a broader use of the Sacred Text in the figurative sense, provided this be done with moderation and restraint; it should, however, never be forgotten that this use of the Sacred Scripture is, as it were, extrinsic to it and accidental, and that, especially in these days, it is not free from danger, since the faithful, in particular those who are well-informed in the sciences sacred and profane, wish to know what God has told us in the Sacred Letters rather than what an ingenious orator or writer may suggest by a clever use of the words of Scripture. Nor does "the word of God, living and effectual and more piercing than any two-edged sword and reaching unto the division of the soul and the spirit, of the joints also and the marrow, and a discerner of the thoughts and intents of the heart" need artificial devices and human adaptation to move and impress souls; for the Sacred Pages, written under the inspiration of the Spirit of God, are of themselves rich in original meaning; endowed with a divine power, they have their own value; adorned with heavenly beauty, they radiate of themselves light and splendor, provided they are so fully and accurately explained by the interpreter, that all the treasures of wisdom and prudence, therein contained are brought to light.
Source: Divino Afflante Spiritu (Vatican.va)