It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) mentioned the five prayers and said: "Whoever guards them, they will be for him a light, a proof (of faith) and a means of salvation on the Day of Resurrection."
This is how it appears in the printed Dar al-Haramain edition, and the correct name is probably Sa'id bin Abi Ayyub.
Hadith Referenceالمعجم الأوسط / باب الألف / 1767
Hadith Takhrij«أخرجه ابن حبان فى «صحيحه» برقم: 1467، والدارمي فى «مسنده» برقم: 2763، وأحمد فى «مسنده» برقم: 6687، وعبد بن حميد فى «مسنده» برقم: 353، والطحاوي فى «شرح مشكل الآثار» برقم: 3180، 3181، والطبراني فى «الكبير» برقم: 14746»