Arabic (Original)
وَبِإِسْنَادِهِ سَمِعْتُ أَبَا الْقَاسِمِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ صُومُوا لِرُؤْيَتِهِ وَأَفْطِرُوا لِرُؤْيَتِهِ فَإِنْ غُمَّ عَلَيْكُمْ فَعُدُّوا ثَلَاثِينَ.
English Translation
And with his chain: I heard Abu al-Qasim (peace and blessings be upon him) say: 'Fast upon sighting it [the new moon], and break the fast upon sighting it. If it is obscured from you, then complete thirty days.'