Matthew 5:27

Ye have heard that it was said
These forms of speech, as well as what follows,

by them of old time,
have been explained, in ver. 21. The law here mentioned,

thou shalt not commit adultery,
is recorded in ( Exodus 20:14 ) and the meaning of our Lord is, not that the then present Jews had heard that such a law had been delivered "to the ancients", their fathers, at Mount Sinai; for that they could read in their Bibles: but they had received it by tradition, that the sense of it, which had been given to their ancestors, by the ancient doctors of the church, was, that this law is to be taken strictly, as it lies, and only regards the sin of uncleanness in married persons; or, what was strictly adultery, and that actual; so that it had no respect to fornication, or unchaste thoughts, words, or actions, but that single act only.