حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا وُهَيْبٌ، حَدَّثَنَا أَيُّوبُ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ بَيْنَا النَّبِيُّ صلى الله عليه وسلم يَخْطُبُ إِذَا هُوَ بِرَجُلٍ قَائِمٍ فَسَأَلَ عَنْهُ فَقَالُوا أَبُو إِسْرَائِيلَ نَذَرَ أَنْ يَقُومَ وَلاَ يَقْعُدَ وَلاَ يَسْتَظِلَّ وَلاَ يَتَكَلَّمَ وَيَصُومَ. فَقَالَ النَّبِيُّ صلى الله عليه وسلم "
مُرْهُ فَلْيَتَكَلَّمْ وَلْيَسْتَظِلَّ وَلْيَقْعُدْ وَلْيُتِمَّ صَوْمَهُ "
Ibn ‘Abbās (may Allah be pleased with him) reported: While the Prophet (may Allah's peace and blessings be upon him) was delivering a sermon, he saw a man who was standing. He asked about him and was told: "This is Abu Isrā’īl. He made a vow to stand in the sun and not sit down, to avoid the shade, to keep silent, and to fast." The Prophet (may Allah's peace and blessings be upon him) said: "Order him to speak, seek the shade, sit down, and complete his fast."
Reported by Al-Bukhari (No. 6704) and Abu Dawud (No. 3300).