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:3:125 –

Yes, if you remain patient and conscious of Allah and the enemy come upon you ˹attacking˺ in rage, your Lord will reinforce you with five thousand angels having marks ˹of distinction˺  

Yea, it is sufficient for you. In ˹sūrat˺ al-Anfāl ˹it is stated˺ with a thousand ˹Q. 8:9˺, because at first He reinforced them with this ˹thousand˺, then it became three ˹thousand˺ then five ˹thousand˺, as God says: if you are patient, in encountering the enemy, and fear, God in not contravening ˹His command˺, and they, the idolaters, come against you instantly, your Lord will reinforce you with five thousand angels accoutred’ (read musawimmīn or musawammīn), that is to say, distinctively marked ˹for the battle˺. Indeed, they were patient and God fulfilled His promise to them, so that the angels fought together with them riding upon piebald horses wearing yellow or white turbans, let loose down to their shoulders.
القرآن:٣:١٢٥ –

بَلَىٰ ۚ إِنْ تَصْبِرُوا وَتَتَّقُوا وَيَأْتُوكُمْ مِنْ فَوْرِهِمْ هَٰذَا يُمْدِدْكُمْ رَبُّكُمْ بِخَمْسَةِ آلَافٍ مِنَ الْمَلَائِكَةِ مُسَوِّمِينَ  

{بلى} يكفيكم ذلك وفي الأنفال بألف لأنه أمدهم أولا بها ثم صارت ثلاثة ثم صارت خمسة كما قال تعالى {إن تصبروا} على لقاء العدو {وتتقوا} الله في المخالفة {ويأتوكم} أي المشركون {من فورهم} وقتهم {هذا يمددكم ربكم بخمسة آلاف من الملائكة مُسَوَّمينَ} بكسر الواو وفتحها أي معلمين وقد صبروا وأنجز الله وعده بأن قاتلت معهم الملائكة على خيل بلق عليهم عمائم صفر أو بيض أرسلوها بين أكتافهم.