What is the ruling on the validity of fasting when one completes thirty days based on one witness's testimony without a physical moon sighting?

General Chapter

Al-Mughni

Book of Fasting

Book 9 · Issue 3 · Bab 1

Open in Qurani

Primary text

One of two scholarly opinions suggests that if people fast thirty days based on a single witness's testimony without seeing the new moon, they must break their fast. This position allows for breaking the fast based on the preceding testimony under specific conditions.

Supporting text

The counter-argument to the above point is twofold: First, breaking the fast based on the testimony is predicated upon having already commenced fasting based on that same testimony; since they did not fast based on the testimony initially, the basis for breaking fast is absent. Second, the Hadith of Kurayb supports the opposing view, validating an independent sighting.