Abd al-A'la narrates: I entered the mosque with Sayyiduna Ibn Mas'ud (may Allah be pleased with him), and he bowed (in prayer). Meanwhile a man passed by him while he was bowing and greeted him with salam. He said: "Allah and His Messenger have spoken the truth." When he finished (the prayer), he said: It used to be said: "Among the signs of the Hour is that a man greets another man only because he knows him, that the mosques are taken as thoroughfares, that women and horses become expensive and then become cheap and never become expensive again until the Day of Resurrection, and that men and women engage in trade together."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9453