Imam Ja’far as-Sadiq (A.S.) says

When a person intends to send a proposal for marriage, he must pray two rak‘at prayers, praise Allah and recite the following invocation: 1

  بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم اَللّهُمَّ اِنِّى اُرِيْدُ اَنْ اَتَزَوَّجَ فَقَدِّرْ لِىْ مِنَ النِّسَّآءِ اَعَفَّهُنَّ فَرْجًا وَّ اَحْفَظَهُنَّ لِىْ فِىْ نَفْسِهَا وَ مَا لِىْ وَ اَوْسَعَهُنَّ لِىْ رِزْقًا وَ اَعْظَمَهُنَّ لِىْ بَرَكَةً فِى نَفْسِهَا وَ مَا لِىْ اَنَّىْ اَتْرُكُ فَقَدِّرْ لِىْ مِنْهَا وَ لَدًا طَيِّبًا تَجْعَلَهُ خَلَفًا صَالِحًا فِىْ .حَيوتِىْ وَ بَعْدَ مَوْتِىْ وَ بَعْدَ مَوْتِىْ

Bismillah hir Rah’maanir Rah’eem Allaahumma inni oreedo an atazawwaja faqaddirli minannisaa-e- a-’affahunna farjawn wa ah’faz’ahunna li fi nafseha wa maali wa aw sa-a’-hunna li rizqan wa a’-z’amahunna li barakatan fi nafseha wa maali anna atroko faqaddirli minha waladan t’ayyaban taj-a’lahu khalafan s’aaleh’an fi h’ayaati wa ba’da mauti.

Translation: In the name of Allah the Beneficent, the Merciful. O Allah! I intend to marry. Therefore destine for me the most chaste of women and one who would, for my sake, guard herself and my property. Who shall be most auspicious for increase in sustenance and bounties. Then from her womb bestow a pure son who would be my sweet reminiscence in my life and after my death.