The Holy Prophet (S) with no regard to the class of the one's generation, emphasized and said: "When someone refers to you for marriage and you approve contently, his manner and his religion, then unite with him in wedlock. If you do not do that, you have caused a grand pest and decadence on the earth."
Al-Tahthib, vol. 7, p. 394
Imam al-Jawad (‘a) wrote in a letter: "Whoever solicits you in marriage and you are convinced of his religion and his honesty, then do unite with him in wedlock."
Al-Kafi, vol. 5, p. 347
Man La Yahdhuruhul-Faqih, vol. 3, p. 393; Al-Tahthib, vol. 7, p. 394
Once a man told Imam Husayn (‘a) that he had a daughter and asked whom he (‘a) would advise him to give her to in marriage, and he said: "Give her in marriage to someone who (has Faith and) fears Allah, Almighty and Glorious, because he will love and respect her, and if he becomes angry with her, he will not hurt her."
Al-Mustatraf, vol. 2, p. 218
The Holy Prophet (S) said: "He who gives his daughter in marriage to an ungodly man has indeed broken off her connection with her kindred."
Al-Muhajjat-ul-Bayda, vol. 3, p. 94