A person being enlightened by a non-enlightened I have heard stories of non-enlightened monks preach dharma to ordinary people and those people would become enlightened (At least a stream-enterer).

Can I have any sources on these? Possibly any sutta sources as well?
One story I remember is from Questions of King Milinda, where Nagasena himself not yet a stream-enterer, preached Abhidharma to a lay lady - as a result of which both the lady and Nagasena have achieved the stream-entry:


  Now a certain woman, a distinguished follower of the faith, had for thirty years and more administered to the wants of the venerable 
  Assagutta. And at the end of that rainy season she came one day to him, and asked whether there was any other brother staying with him. And 
  when she was told that there was one, named Nagasena, she invited the Elder, and Nagasena, with him, to take their midday meal the next day at 
  her house. And the Elder signified, by silence, his consent. The next forenoon the Elder robed himself, and taking his bowl in his hand, went 
  down, accompanied by Nagasena as his attendant, to the dwelling-place of that disciple, and there they sat down on the seats prepared for them. And she gave to both of them food, hard and soft, as much as they required, waiting upon them with her own hands. When Assagutta had finished his meal, and the hand was withdrawn from the bowl, he said to Nagasena: 'Do thou, Nagasena, give the thanks to this distinguished lady.' And, so saying, he rose from his seat, and 
  went away.  
  
  And the lady said to Nagasena: 'I am old, friend Nagasena. Let the thanksgiving be from the deeper things of the faith.'  
  
  And Nagasena, in pronouncing the thanksgiving discourse, dwelt on the profounder side of the Abhidhamma, not on matters of mere ordinary morality, but on those relating to Arahatship. And as the lady sat there listening, there arose in her heart the Insight into the Truth, clear and stainless, which perceives that "whatsoever has beginning, that has the inherent quality of passing away". And Nagasena also, when he had concluded that thanksgiving discourse, felt the force of the truths he himself had preached, and he too arrived at insight he too entered, as he sat there, upon the stream.  
  
  Then the venerable Assagutta, as he was sitting in his arbour, was aware that they both had attained to insight, and he exclaimed: 'Well done! 
  well done, Nagasena! by one arrow shot you have hit two noble quarries!' And at the same time thousands of the gods shouted their approval. 


An alternative translation of the same paragraph:


  And venerable Nagasena pronounced for her a sermon on the Abhidharma, about things deep in their meaning, transcendent, dealing with emptiness, [in accordance with the law of dependent co-arising. That is to say: When this exists, that exists; when this arises, that arises.] And right there and then, even before the lay lady could raise from her seat, there arose in her the dust-free, crystal-clear Vision of Dharma: "Whatever is conditional can be controlled". And venerable Nagasena himself, as he was gratifying the lay lady with his sermon, reflected upon the Dharma he was expounding and had himself attained the insight; and even before he could raise from his seat, he had attained the fruit of stream-entry.