Muʿadh bin Jabal used to pray with the Prophet ﷺ and then go to lead his people in prayer. Once he led the people in prayer and recited Surat-al-Baqara. A man left (the row of the praying people) and offered (light) prayer (separately) and went away. When Muʿadh came to know about it, he said. "He (that man) is a hypocrite." Later that man heard what Muʿadh said about him, so he came to the Prophet and said, "O Messenger of Allah ﷺ! We are people who work with our own hands and irrigate (our farms) with our camels. Last night Muʿadh led us in the (night) prayer and he recited Sura-al-Baqara, so I offered my prayer separately, and because of that, he accused me of being a hypocrite." The Prophet called Muʿadh and said thrice, "O Muʿadh! You are putting the people to trials? Recite 'Washshamsi wad-uhaha' (91) or'Sabbih isma Rabbi ka-l-A'la' (87) or the like."  

أَنَّ مُعَاذَ بْنَ جَبَلٍ ؓ كَانَ يُصَلِّي مَعَ النَّبِيِّ ﷺ ثُمَّ يَأْتِي قَوْمَهُ فَيُصَلِّي بِهِمُ الصَّلاَةَ فَقَرَأَ بِهِمُ الْبَقَرَةَ قَالَ فَتَجَوَّزَ رَجُلٌ فَصَلَّى صَلاَةً خَفِيفَةً فَبَلَغَ ذَلِكَ مُعَاذًا فَقَالَ إِنَّهُ مُنَافِقٌ فَبَلَغَ ذَلِكَ الرَّجُلَ فَأَتَى النَّبِيَّ ﷺ فَقَالَ يَا رَسُولَ اللَّهِ إِنَّا قَوْمٌ نَعْمَلُ بِأَيْدِينَا وَنَسْقِي بِنَوَاضِحِنَا وَإِنَّ مُعَاذًا صَلَّى بِنَا الْبَارِحَةَ فَقَرَأَ الْبَقَرَةَ فَتَجَوَّزْتُ فَزَعَمَ أَنِّي مُنَافِقٌ فَقَالَ النَّبِيُّ ﷺ يَا مُعَاذُ أَفَتَّانٌ أَنْتَ ثَلاَثًا اقْرَأْ {وَالشَّمْسِ وَضُحَاهَا} وَ{سَبِّحِ اسْمَ رَبِّكَ الأَعْلَى} وَنَحْوَهَا  

Messenger of Allah ﷺ said: "Whoever amongst you swears, (saying by error) in his oath 'By Al-Lat and Al- Uzza', then he should say, 'None has the right to be worshipped but Allah.' And whoever says to his companions, 'Come let me gamble' with you, then he must give something in charity (as an expiation for such a sin)." (See Hadith No. 645)  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ حَلَفَ مِنْكُمْ فَقَالَ فِي حَلِفِهِ بِاللاَّتِ وَالْعُزَّى فَلْيَقُلْ لاَ إِلَهَ إِلاَّ اللَّهُ وَمَنْ قَالَ لِصَاحِبِهِ تَعَالَ أُقَامِرْكَ فَلْيَتَصَدَّقْ  

that he found ʿUmar bin Al-Khattab in a group of people and he was swearing by his father. So Messenger of Allah ﷺ called them, saying, "Verily! Allah forbids you to swear by your fathers. If one has to take an oath, he should swear by Allah or otherwise keep quiet."  

أَنَّهُ أَدْرَكَ عُمَرَ بْنَ الْخَطَّابِ فِي رَكْبٍ وَهْوَ يَحْلِفُ بِأَبِيهِ فَنَادَاهُمْ رَسُولُ اللَّهِ ﷺ أَلاَ إِنَّ اللَّهَ يَنْهَاكُمْ أَنْ تَحْلِفُوا بِآبَائِكُمْ فَمَنْ كَانَ حَالِفًا فَلْيَحْلِفْ بِاللَّهِ وَإِلاَّ فَلْيَصْمُتْ