Quotations from Early Church Fathers

Tertullian

“Let him who contends that the Sabbath is still to be observed as a balm
of salvation, and circumcision on the eighth day . . . teach us that, for
the time past, righteous men kept the Sabbath or practiced circumcision,
and were thus rendered ‘friends of God.’ For if circumcision purges a man,
since God made Adam uncircumcised, why did he not circumcise him, even
after his sinning, if circumcision purges? . . . Therefore, since God
originated Adam uncircumcised and unobservant of the Sabbath, consequently
his offspring also, Abel, offering him sacrifices, uncircumcised and
unobservant of the Sabbath, was by him [God] commended [Gen. 4:1-7, Heb.
11:4]. . . . Noah also, uncircumcised-yes, and unobservant of the
Sabbath-God freed from the deluge. For Enoch too, most righteous man,
uncircumcised and unobservant of the Sabbath, he translated from this
world, who did not first taste death in order that, being a candidate for
eternal life, he might show us that we also may, without the burden of the
law of Moses, please God” (An Answer to the Jews 2 [A.D. 203]).

 

Eusebius of Caesarea

“They [the early saints of the Old Testament] did not care about
circumcision of the body, neither do we [Christians]. They did not care
about observing Sabbaths, nor do we. They did not avoid certain kinds of
food, neither did they regard the other distinctions which Moses first
delivered to their posterity to be observed as symbols; nor do Christians
of the present day do such things” (Church History 1:4:8 [A.D. 312]).

Source: http://www.catholic.com/library/sabbath_or_sunday.asp