Sunan an-Nasa'i, Hadith 2277 ⓘ
It was narrated from Abu Qilabah that a man said: "I came to the Prophet to discuss something and he was eating breakfast. He said: 'Come and eat.' I said: 'I am fasting.' He said: 'Come and I will tell you about fasting. Allah has waived half of prayer and fasting from the traveler, and he has granted a concession to pregnant women and the sick."'
أَخْبَرَنَا سُوَيْدُ بْنُ نَصْرٍ، قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ، عَنْ خَالِدٍ الْحَذَّاءِ، عَنْ أَبِي قِلاَبَةَ، عَنْ رَجُلٍ، قَالَ أَتَيْتُ النَّبِيَّ صلى الله عليه وسلم لِحَاجَةٍ فَإِذَا هُوَ يَتَغَدَّى قَالَ " هَلُمَّ إِلَى الْغَدَاءِ " . فَقُلْتُ إِنِّي صَائِمٌ . قَالَ " هَلُمَّ أُخْبِرْكَ عَنِ الصَّوْمِ إِنَّ اللَّهَ وَضَعَ عَنِ الْمُسَافِرِ نِصْفَ الصَّلاَةِ وَالصَّوْمَ وَرَخَّصَ لِلْحُبْلَى وَالْمُرْضِعِ " .
also referenced under: Book 22, Hadith 188 (In-Book) & Volume 3, Book 22, Hadith 2279 (DarusSalam)