What are the sources for the statements of Ali ibn Abi Talib and Abu Hanifa regarding the obligation of qada' (making up the fast) only for pregnant and breastfeeding women if they break their fast?

It was reported from Abu Hanifa and his students that if a pregnant or nursing woman fears for her child or herself during Ramadan, she may break her fast and must make up the days later. Neither an expiatory payment (sadaqa) nor a compensation (kaffara) is required of them. This is considered a sickness among sicknesses. This opinion has also been reported from Ali ibn Abi Talib and Ibn Abbas, may Allah be pleased with them.