It is narrated from Sayyiduna Zayd bin Arqam (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever says 'La ilaha illallah' (There is no god but Allah) with sincerity will enter Paradise." It was said: "And what is its sincerity?" He (peace and blessings be upon him) said: "That it (this word) holds him back from the things Allah, the Mighty and Majestic, has made unlawful."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Abu Ishaq (may Allah have mercy on him) except Sharik (may Allah have mercy on him), and Muhammad bin Abd al-Rahman (may Allah have mercy on him) is alone in narrating it from him."
Hadith Referenceالمعجم الأوسط / باب الألف / 1235
Hadith Gradingمحدثین:إسناده ضعيف جدًّا، فيه محمد بن عبد الرحمن بن غزوان وضاع
Hadith Takhrij«قال الهيثمي: في إسناده محمد بن عبد الرحمن بن غزوان وهو وضاع «مجمع الزوائد ومنبع الفوائد، ج 1، ص 18»» «أخرجه الطبراني فى «الكبير» برقم: 5074»