It appears in chapter thirteen of this letter:

           We follow what is written, because the Holy Spirit has said that a wise man is never proud of his wisdom. And we should keep in mind the words of Christ who said at the time of preaching patience and practice:

           ”Be ye merciful, that ye be shown mercy, forgive that ye he forgiven; ye will be acted upon, the same as you will act upon others, as you will give so shall you be given, you will be judged as you will judge upon others; as you will pity, so shall you be pitied upon and with the same measure that ye mete withal it shall be measured to You again.”

           The Christians claim that this passage was taken by Clement from Luke 6:36-38 and Matt.7: 1,2,12. The passage from the Luke is this:

           Be ye therefore merciful, as your Father also is merciful. Judge not, and ye shall not be judged: condemn not, and ye shall not be condemned: forgive, and ye shall be forgiven: Give, and it shall be given unto you; good measure, pressed down, shaken together, and running over, shall men give into your bosom. For with the same measure that ye mete withal it shall be measured to you mete.

 The passage from Matthew 7:1,2 reads:

           Judge not, that ye be not judged. For with what judgment ye judge, ye shall be judged: and with what measure ye mete, it shall be measured to you again.

 And in verse 12:

           Therefore all things whatsoever ye would that men should do to you, do ye even so to them: for this is the law and the prophets.