My mother-in-law has been suffering from diabetes for many years. In spite of this, she used to fast. This year, however, her sickness became even worse. The doctor ordered her to take an insulin injection three times a day. She is 74 years old. Does this injection break the fast? Is it obligatory for her to fast?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Insulin injections do not break the fast because they are not food or drink, neither do they have the same effect as food and drink. In principle, a person's fasting is valid, thus, such principle cannot be removed except by textual evidence. Therefore, your mother-in-law's fasting is valid. However, if she is told by a trustworthy doctor that fasting is harmful to her, then it is permissible for her to not fast. Nevertheless, she then has to give food to one poor person for each day that she does not fast. This is based on the statement of Allaah Almighty (which means): {And upon those who are able [to fast, but with hardship]—a ransom [as substitute] of feeding a poor person [each day].} [Quran 2: 184]

Ibn ‘Abbas said: “This was a concession granted to old men and women who are not able to fast. They are obliged to feed one poor person for each day that they miss.” [Al-Bukhari]

Allaah Knows best.