The Ruling of the Moon Sighting For the One Who Sees the New Moon by Himself

Excerpts from the ‘Jurisprudence of Worship’
By Shaykh Muhammad ibn Saalih ibn Uthaymeen رحمه الله تعالى

بسم الله الرحمن الرحيم

Question: Oh Noble Shaykh, What is ruling of the one who sees the new Moon (of Ramadān) by himself and the people do not fast with him?
Answer:
Whomever sees the new crescent moon (of Ramadān) by himself is obligated to inform his sighting to his authorities in the Islamic Courts and he should bear witness to his testimony. (To those that live in Muslim lands where the Islamic laws are applied).
And the entering of the Blessed Month of Ramadān is determined by one testimony of one person if a judge is content with his testimony and rules based on his testimony.
And in the case that his testimony is rejected, some of the scholars have said it is obligatory that he (the one who has witnessed the moon sighting) fasts. Due to the fact he is certain he has seen the new crescent moon.
And verily The Prophet ﷺ said,
“Observe fast when you see it (new crescent moon of Ramadān)”.¹
Certainly, this one has seen it. (So he is to observe fast due to his sighting of the new crescent moon).
And some other scholars have said: it is not obligatory upon him to fast because fasting is a day where the people fast and breaking fast is upon a day where the people break their fast, and his concurrence and his agreement with the rest of Muslims is better than his singularity and divergence (from them and their position).
And some other Scholars separated these positions and said it is obligatory upon him to fast in secret. It is obligatory upon him to fast because he has seen the new crescent moon of Ramadān and he fasts in secret to avoid showing opposition and difference from the general body of the Muslims.

¹ Related by Bukhari- The Book of Fasting [Number 1909] and related by Muslim- The Book of Fasting- [Number 1081].
Jurisprudence of Worship- Fatwa Regarding Sâum (Fasting). By Shaykh Muhammad ibn Saalih Ibn Uthaymeen (pg.248)

Translated by: Abu Uwāis Muhammad Abdullahi Elmi