Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:40:51 –

Indeed, We will support Our messengers and those who believe during the life of this world and on the Day when the witnesses will stand -  

Truly We shall help Our messengers and those who believe, in the life of this world and on the day when the witnesses rise up (ashhād is the plural of shāhid) — these are the angels, who will testify in support of the messengers, that they indeed delivered ˹their Messages˺, and against the disbelievers, that they denied ˹them˺;
القرآن:٤٠:٥١ –

إِنَّا لَنَنْصُرُ رُسُلَنَا وَالَّذِينَ آمَنُوا فِي الْحَيَاةِ الدُّنْيَا وَيَوْمَ يَقُومُ الْأَشْهَادُ  

{إنا لننصر رسلنا والذين آمنوا في الحياة الدنيا ويوم يقوم الأشهاد} جمع شاهد، وهم الملائكة يشهدون للرسل بالبلاغ وعلى الكفار بالتكذيب.