Mishkat al-Masabih #242

‘Abdallah b. ‘Amr told of God’s messenger coming upon two groups in his mosque and saying, “They are both engaged in what is good, but one of them is superior to the other. These ones are praying and supplicating God who, if He wills, may answer their prayers but, if He wills, may refuse them. Those ones are learning knowledge* and teaching the ignorant, so they are superior. I was sent only as a teacher.” He then sat down among them. Darimi transmitted it. *The text has al-fiqh au al-'ilm, fiqh and ‘ilm having the same meaning, but the transmitter of the tradition was not sure which word was used by the Prophet on this occasion.