أَخْبَرَنَا هَارُونُ بْنُ إِسْحَاقَ، قَالَ حَدَّثَنَا الْمُحَارِبِيُّ، عَنِ الأَعْمَشِ، عَنْ إِبْرَاهِيمَ، عَنْ عَلْقَمَةَ، وَالأَسْوَدِ، عَنْ عَبْدِ اللَّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ مَنِ اسْتَطَاعَ مِنْكُمُ الْبَاءَةَ فَلْيَتَزَوَّجْ وَمَنْ لَمْ يَجِدْ فَعَلَيْهِ بِالصَّوْمِ فَإِنَّهُ لَهُ وِجَاءٌ ‏"‏ ‏.‏

It was narrated that 'Abdullah said: "The Messenger of Allah said: 'Whoever among you can afford to get married, let him do so, and whoever cannot afford it should fast, for it will be a restraint (Wija) for him."' Translation Not Available

Book Ref: Sunan An Nisai Book 22 Hadith 2241
Web Ref:  Sunan An Nisai Vol 3 Book 22 Hadith 2243