From the Gospel according to Matthew
Jesus said to his disciples: "You have heard that it was said to your ancestors, Do not take a false oath, but make good to the Lord all that you vow. But I say to you, do not swear at all; not by heaven, for it is God's throne; nor by the earth, for it is his footstool; nor by Jerusalem, for it is the city of the great King. Do not swear by your head, for you cannot make a single hair white or black. Let your 'Yes' mean 'Yes,' and your 'No' mean 'No.' Anything more is from the Evil One."
The Gospel of the Lord.
Praise to you, Lord Jesus Christ.