It is narrated from Shaqiq (may Allah have mercy on him) that Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) met Sayyiduna Talhah (may Allah be pleased with him) and asked: "Why is it that I see you in a state of deep sorrow and dejection?" He replied: "It is nothing, except for one word which I heard the Messenger of Allah (peace and blessings be upon him) say: 'It is certainly a word that makes (Paradise) obligatory,' but I was not able (out of extreme reverence or for some reason) to ask him (peace and blessings be upon him) which word it was." Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) said: "But I know that word." He asked: "What is it?" Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) said: That word is "La ilaha illallah" (there is no god worthy of worship except Allah).
This chain is hasan (good) provided that Shaqiq's hearing from Sayyiduna Talhah (may Allah be pleased with him) is established, and this hadith is gharib (singular) as a narration of Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him).
Furthermore, Ishaq narrated through Jarir, Mansur and Shaqiq that he said: I was told that Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) met Sayyiduna Talhah (may Allah be pleased with him), and then he mentioned it in the same way as the above report.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب الإيمان والتوحيد / 2858
Hadith Gradingمحدثین:إسناده حسن
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :قال ابن حجر: هَذَا إِسْنَادٌ حَسَنٌ إِنْ كَانَ شَقِيقٌ سَمِعَهُ مِنْ طَلْحَةَ ، وَهُوَ غَرِيبٌ مِنْ حَدِيثِ أَبِي بَكْرٍ . » «أخرجه مسند أبي يعلى برقم: 102، وأخرجه المطالب العالية لابن حجر برقم: 2858 / 2»