Need reference for the two conditions need to realize path to Nibbana In this article, it has mentioned that;


  During the time of the Buddha there were two ways by which one could understand the Dhamma and realise the path to Nibbana. One is called “paratoghosa paccaya.” Hearing the true Dhamma from others who know it. The other is called “sammasati” or practice of meditation.


Would anyone please give me reference from Pali canon or any other book for the above statement?
I didn't find that phrase on sutta central. https://suttacentral.net/search?query=paratoghosa

Still it's very common in the suttas to read of someone's entering the stream at the end of a sutta. Perhaps the first time that happens is in the first sutta, SN 56.11,


  That is what the Blessed One said. Gratified, the group of five monks delighted at his words. And while this explanation was being given, there arose to Ven. Kondañña the dustless, stainless Dhamma eye: Whatever is subject to origination is all subject to cessation.


Perhaps that's the most common way or almost the only way these days. The article you quoted said that "sammasati" is the method which the Buddha himself used (perhaps because he couldn't hear the Buddha-dhamma from someone else).

Note that "sammasati" doesn't just mean "meditation", it's also "right mindfulness" i.e. part of the noble eightfold path. So I suppose people won't complete the path without that, but they might enter the path (and I think that must be what was meant by "realise" the path).