Sahih Muslim #2530 · The Book of Fasting

Sahih MuslimAbu'l-Bakhtari reported
Sahih Muslim · Book 13 · The Book of Fasting
Sahih Muslim · كتاب 13 · كتاب الصيام
We saw the new moon of Ramadan as we were at Dhit-i-'Irq. We sent a man to Ibn Abbas (Allah be pleased with both of them) to ask him (whether the sighting of a small moon had something of the nature of defect in it). Upon this Ibn 'Abbas (Allah be pleased with both of them) said that the Messenger of Allah (ﷺ) had said: Verily Allah deferred its sight, but if (the new moon) is hidden from you, then, complete its number (thirty).
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا غُنْدَرٌ، عَنْ شُعْبَةَ، ح وَحَدَّثَنَا ابْنُ الْمُثَنَّى، وَابْنُ، بَشَّارٍ قَالاَ حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، أَخْبَرَنَا شُعْبَةُ، عَنْ عَمْرِو بْنِ مُرَّةَ، قَالَ سَمِعْتُ أَبَا الْبَخْتَرِيِّ، قَالَ أَهْلَلْنَا رَمَضَانَ وَنَحْنُ بِذَاتِ عِرْقٍ فَأَرْسَلْنَا رَجُلاً إِلَى ابْنِ عَبَّاسٍ - رضى الله عنهما - يَسْأَلُهُ فَقَالَ ابْنُ عَبَّاسٍ - رضى الله عنهما - قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏
"‏ إِنَّ اللَّهَ قَدْ أَمَدَّهُ لِرُؤْيَتِهِ فَإِنْ أُغْمِيَ عَلَيْكُمْ فَأَكْمِلُوا الْعِدَّةَ ‏"‏ ‏.‏
Reference : Sahih Muslim 2530In-book reference : Book 13, Hadith 36