Deuteronomy 30:12-14

In heaven Shut up there, but it hath been thence delivered and published in thy hearing. Neither beyond the sea The knowledge of this commandment is not to be fetched from far distant places, to which divers of the wise heathen travelled for their wisdom; but it was brought to thy very doors and ears, and declared to thee in this wilderness. In thy mouth Thou knowest it so well, that it is the matter of thy common discourse. In thy heart In thy mind, (as the heart is very commonly taken,) to understand and believe it. In a word, the law is plain and easy: but the gospel is much more so.