Sunan Abi Dawud 2318
Narrated Abdullah ibn Abbas:
Explaining the verse; "For those who can do it (with hard-ship) is a ransom, the feeding of one, that is indigent," he said: This was a concession granted to the aged man and woman who were able to keep fast; they were allowed to leave the fast and instead feed an indigent person for each fast; (and a concession) to pregnant and suckling woman when they apprehended harm (to themselves).
حَدَّثَنَا ابْنُ الْمُثَنَّى، حَدَّثَنَا ابْنُ أَبِي عَدِيٍّ، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، عَنْ عَزْرَةَ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عَبَّاسٍ، ‏{‏ وَعَلَى الَّذِينَ يُطِيقُونَهُ فِدْيَةٌ طَعَامُ مِسْكِينٍ ‏}‏ قَالَ كَانَتْ رُخْصَةً لِلشَّيْخِ الْكَبِيرِ وَالْمَرْأَةِ الْكَبِيرَةِ وَهُمَا يُطِيقَانِ الصِّيَامَ أَنْ يُفْطِرَا وَيُطْعِمَا مَكَانَ كُلِّ يَوْمٍ مِسْكِينًا وَالْحُبْلَى وَالْمُرْضِعُ إِذَا خَافَتَا - قَالَ أَبُو دَاوُدَ يَعْنِي عَلَى أَوْلاَدِهِمَا - أَفْطَرَتَا وَأَطْعَمَتَا ‏.‏