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 ‏"‏ ‏.‏

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."' Translation Not Available

Book Ref: Sunan An Nisai Book 22 Hadith 2277
Web Ref:  Sunan An Nisai Vol 3 Book 22 Hadith 2279