Al-Imaam Ibn Al-‘Uthaymeen (rahimahullaah) talks about the person who narrates a hadeeth but not in its exact wording
Question: The questioner also says, “Is it permissible for the Muslim person who is devoted to studying and understanding his religion, to give talks of admonition but he says hadeeths, for example, but not with the exact wording. Is there any sin upon him regarding that?”
Answer: This which he (the questioner) mentions, it means that he (the speaker) wants to relate the hadeeth according to the meaning, and relating hadeeths by the meaning, the scholars of hadeeth have differed about it as to whether or not it is permissible. So from among them there are those who consider it to be permissible
under the condition that the person who is speaking knows the meaning, and that the hadeeth that he is relating by its meaning, nothing of it is changed.
And another condition is that he fully grasps from the hadeeth that which is obligatory to be fully understood of it such that he does not cut out from it anything which relates to what he has mentioned (in his speech). Thus, if he knows the meaning and he fully grasps the hadeeth in a way in which there is no defect in it (his understanding of the hadeeth), then the correct view is that it is permissible. The correct view is that it is permissible (the Shaikh repeats). However, he must finish it with his saying ‘or as the Prophet (sallallaahu ‘alayhi wa sallam) said’, so that he does not cause anyone to memorize it how he said it, thinking that it is the actual wording of the hadeeth from the Messenger (‘alayhis-salaatu was-salaam).
Source: The program Noorun ‘alaa ad-Darb, transcribed on the web page at the link
http://www.ibnothaimeen.com/all/noor/article_6354.shtml