I would say here something that was heard from an ecclesiastic of the most eminent degree; “That the intention of the Holy Ghost is to teach us how one goes to heaven, not how the heaven goes.”

[Lo qui direi che quello che intesi da persona ecclesiastica costituita in eminentissimo grado, ciò è l’intenzione dello Spirito Santo essere d’insegnarci come si vadia al cielo, e non come vadia il cielo.]

Galileo Galilei (1564–1642) Italian astronomer, physicist, engineer, polymath

Letter (1615) to Christina of Lorraine, Grand Duchess of Tuscany [tr. Drake (1957)]
    (Source)

Arguing that the Bible not being clear on the question of heliocentrism is unimportant; that the purpose of the Bible is the highest, salvation of the soul, not to explain the mechanics of the universe.

(Source (Italian))

While often attributed directly to Galileo, he is clearly quoting someone, generally thought to be Cardinal Caesar Baronius (1538–1607), with whom he was acquainted. For more see here.

Variant: "The Bible teaches us how to go to heaven, not how the heavens go."