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
bayhaqi:9003 – Abū al-Ḥusayn b. al-Faḍl al-Qaṭṭān > ʿAbdullāh b. Jaʿfar > Yaʿqūb b. Sufyān > Muḥammad b. al-Muthanná > Yaʿlá b. ʿUbayd > Muḥammad b. Isḥāq > Muḥammad b. Shihāb > Yaḥyá b. ʿAbbād > ʿAbbād / Ibn ʿAbdullāh b. al-Zubayr > Ḥudditht > ʿUmar

[Machine] Here I am, O Allah, here I am.  

البيهقي:٩٠٠٣ – وَأَخْبَرَنَا أَبُو الْحُسَيْنِ بْنُ الْفَضْلِ الْقَطَّانُ أنبأ عَبْدُ اللهِ بْنُ جَعْفَرٍ ثنا يَعْقُوبُ بْنُ سُفْيَانَ ثنا مُحَمَّدُ بْنُ الْمُثَنَّى ثنا يَعْلَى بْنُ عُبَيْدٍ ثنا مُحَمَّدُ بْنُ إِسْحَاقَ عَنْ مُحَمَّدِ بْنِ شِهَابٍ عَنْ يَحْيَى بْنِ عَبَّادٍ عَنْ عَبَّادٍ يَعْنِي ابْنَ عَبْدِ اللهِ بْنِ الزُّبَيْرِ قَالَ حُدِّثْتُ أَنَّ عُمَرَ بْنَ الْخَطَّابِ ؓ لَمَّا دَخَلَ بَيْتَ الْمَقْدِسِ قَالَ

لَبَّيْكَ اللهُمَّ لَبَّيْكَ