Reports on "La ilaha illallah wallahu akbar"

Mu'adh bin Abdullah bin Rafi' states: I was present in a gathering in which Sayyiduna Abdullah bin Umar (may Allah be pleased with them both), Sayyiduna Abdullah bin Ja'far (may Allah be pleased with him) and Abd al-Rahman bin Abi Amrah were present. Ibn Abi Amrah said: I heard Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) relate; he said: I heard the Prophet (peace and blessings be upon him) say: "There are two phrases: one of them has no barrier short of the Throne, and the other fills the space between the heaven and the earth: 'La ilaha illallah, wallahu akbar' (There is no deity except Allah, and Allah is the Greatest)." Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said to Ibn Abi Amrah: "Did you yourself hear Sayyiduna Mu'adh (may Allah be pleased with him) relate this?" He replied: "Yes!" The narrator states: Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) began to weep until his beard was wet with tears, and he said: "These are two phrases that we used to recite and to which we were devoted."
Tabarani recorded it. I do not know the narrator named Mu'adh bin Abdullah bin Rafi'; one narrator is Ibn Lahi'ah, whose hadith is hasan (good); the rest of its narrators are thiqat (trustworthy).

Sayyiduna Abu al-Darda' (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "Whoever recites 'La ilaha illallahu wallahu akbar' (There is no deity except Allah, and Allah is the Greatest), Allah Almighty frees a quarter of that person's being from Hell; whoever recites it twice, Allah Almighty frees half of his being from Hell; and if that person recites it four times, Allah Almighty frees him from Hell."
Tabarani recorded it in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat; both contain a narrator, Abu Bakr bin Abi Maryam, who is da'if (weak).