Zirr bin Hubaysh narrates: Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) had with him a young man (ghulam) who used to read the Mushaf, and his companions were present with him. A man named Hasramah came and said: "O Abu Abd al-Rahman, which degree of Islam is most excellent?" He replied: "Prayer." He asked: "Then which?" He replied: "Zakah."
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators have been declared trustworthy.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الزكاة / 4368